THE NORTH AMERICAN SLIME-MOULDS

THE MYXOMYCETES (Link) DeBary

Chlorophyl-less organisms whose vegetative phase consists of a naked mass of multinuclear protoplasm, the plasmodium; reproduced by spores which are either free or more commonly enclosed in sporangia, and which on germinating produce ciliated or amœboid zoöspores, whose coalescence gives rise to the plasmodium.

The Myxomycetes are,—

A. Parasites, in the cells of living plantsPhytomyxinæ

B. Saprophytes, developed in connection with decaying vegetable matter:

a. With free sporesExosporeæ

b. With spores in receptacles or sporangiaMyxogastres

Sub-Class PHYTOMYXINÆ Schroeter

1889. Phytomyxinae Schroeter, Engl. u. Prantl., I., i., pp. 1 and 5.

The parasitic Myxomycetes affecting plants include but few (four or five) species, distributed among four genera. All are parasites in the cells of particular hosts; their vegetative phase is plasmodial and their spores are formed by the simultaneous breaking up of the plasmodium into an indefinite number of independent cells. But a single genus need here concern us,—

Plasmodiophora Woronin

1879. Plasmodiophora Woronin, Pringsh. Jahrb., XI., p. 548.

Parasitic in the parenchymatous cells of the roots of living plants, causing noticeable enlargement of the affected organ, producing at length galls, knots, and various deformities and distortions. Spores spherical, smooth, colorless, 16 µ.

I. Plasmodiophora brassicæ Woronin.

1879. Plasmodiophora brassicae Woronin, op. cit.

This species, typical of forms so far reported in this country, infests the roots of cabbages,[15] and produces a very serious disease of that vegetable. In England the malady has long been known under the names "clubbing," "fingers and toes," etc. The roots affected swell greatly, and at length resemble sometimes the flexed fingers of the human hand; hence the English name. As the disease progresses, the roots speedily rot away, to the serious injury of the leaf-bearing portion of the plant. In badly affected fields, sometimes one-half of the crop is utterly destroyed. Careful search continued through several years has not availed to bring this species to my personal acquaintance.

For a full account of the parasitism of this species and its distribution in the United States see Jour. Myc., VII., p. 79; also Bull. 66, Agric. Sta. of Vermont.

Sub-Class EXOSPOREÆ Rost.

1873. Exosporeae Rostafinski, Versuch, p. 2.

Spores developed, superficially, outside the fructification, which consists of sporophores, membranous, or slender and branching; spores white, stalked. A single genus,—

Ceratiomyxa Schroeter

1889. Ceratiomyxa Schroeter, Engl. u. Prantl, I., i., p. 16. For further synonymy, see under first species.

Sporangia none; spores superficial, borne on erect papillæ or pillars, or even on the inside of minute depressions or pits; each spore surmounting a delicate pedicel or stalk. The spores on germinating give rise to amœboid zoöspores, which undergo repeated divisions, later become ciliate, and at length again amœboid to blend into genuine plasmodia. At maturity the plasmodium gives rise to numerous minute divisions, each of which may lengthen in a direction perpendicular to the surface and bear a spore at the tip.

The homologies between the structures just described and the fructification of the ordinary slime-mould are somewhat obscure, if indeed any really exist. Are these minute reproductive bodies spores?—their behavior on germination is unique; are they sporangia?—the arrested development they exhibit is none the less puzzling. Perhaps the sporiferous pillars represent incipient stipes, the spores the uncombined fragments of what might otherwise have coalesced at the summit of the pillar to form a true sporangium.[16]

Several species have been recognized, all referable probably to one or two, or at most, four forms. That universally recognized alike in the literature of the past and in recent studies is,—

1. Ceratiomyxa fruticulosa (Muell.) Macbr.

Plate I., Figs. 7 and 7 a.

1729. Puccinia ramosa, bifurcata, etc. Micheli, p. 213, Tab. 92, Fig. 2.

1775. Byssus fruticulosa Müller, in Fl. Dan., t. 718, Fig. 2.

1778. Tremella hydnoidea Jacquin, Misc., Vol. I., t. 16.

1783. Clavaria puccinia Batsch, Elench. Fung., p. 139, Fig. 19.

1791. Puccinia byssoides Gmelin, Syst. Naturae, p. 1462.

1791. Clavaria byssoides Bulliard, Champ. de la France, t. 415, Fig. 2.

1794. Isaria mucida Pers., Römer, N. Mag. Bot., I., p. 121.

1801. Isaria mucida Pers., Syn. Meth., p. 688.

1805. Ceratium hydnoides Alb. & Schw., Consp. Fung., p. 258.

1811. Ceratiomyxa porioides (A. & S.) Schroet., Mycet., p. 26, var.

1829. Ceratium hydnoides Fries, Syst. Myc., III., p. 294.

1872. Ceratium hydnoides Wor. & Fam., Mem. Acad. Imp., Petersburg.

1887. Ceratium hydnoides DeBary, Comp. Morph. Fung., p. 432.

1889. Ceratiomyxa mucida Schroeter, Engl. u. Prantl Nat. Pflanz., I., i., p. 16.

1893. Ceratiomyxa mucida, Pers., Macbr., Bull. Nat. Hist. Iowa, II., p. 114.

1894. Ceratiomyxa mucida Schroet., Lister, Mycetozoa, p. 25.

Plasmodium in rotten wood, white or nearly transparent; when fruiting, forming on the substratum mould-like patches composed of the minute sporiferous pillars, generally in clusters of three or more together; spores white, ovoid, or ellipsoidal, smooth, 10–12 × 6 µ.

Very common, occurring in summer on shaded rotten logs, especially after warm showers and in sultry weather. Easily distinguishable from all similar moulds by the absence of mycelium or of anything like a hypha. In Europe the plant seems to be in autumn exceedingly common. Micheli not only described the form but figured it, nearly two hundred years ago. Micheli's figure is good, as is that of Mueller, Fl. Dan., l. c. Mueller referred the species to a Linnean genus Byssus, which seems to have included Algæ rather than anything else, if one can determine its limits at all. The same thing is true of Tremella; but this name is now otherwise applied, as are all the other generic names down to Ceratium, Alb. & Schw. But this had been by Schrank preoccupied, 1793. See the reference above for 1889. As for specific name, there seems no reason to depart from the rule of priority, since Mueller's work is determinative.

Ceratiomyxa arbuscula, Berk. & Br., apparently a form of this, is cited from Toronto by Miss Currie. Massee gives it recognition; Lister as varietal. The sporophores are inclined to be simple, stipitate and dendroid.

C. filiforme of the English authors latest named is a wonderful thing and deserves a paragraph here, if not recognition as a distinct species. It occurs rarely; but once it appears, attracts attention. As in the historic species, the sporifers are white, stand more or less erect, but are every way finer and larger. Each individual sporifer rises like a stiff stem, as of white thread, 2–3 mm. high; at top a tuft of fruiting branchlets, more or less distinct. All taken together, we have a dense mat completely concealing the substratum and spreading out sometimes over an area of surprising extent, several centimetres square.

Common everywhere in summer on decaying sticks and wood of every description, especially in wet places. Alaska to Nicaragua, and probably around the world.

2. Ceratiomyxa porioides (Alb. & Schw.) Schroeter.

1805. Ceratium porioides Alb. & Schw., Consp. Fung., p. 359.

1829. Ceratium porioides Fries, Syst. Myc., III., p. 295.

1873. Ceratium porioides Fam. & Wor. Acad. Imp., XX., 3, p. 5.

1889. Ceratiomyxa porioides Schroet., Engl. u. Prantl, I., i., p. 16.

1894. Ceratiomyxa mucida Schrœt. var. porioides Lister, Mycetozoa, p. 26.

1899. Ceratiomyxa porioides Alb. & Schw. (Schroet.), Macbr., N. A. S., p. 19.

1911. Ceratiomyxa porioides Alb. & Schw., Schroet., List. Mycet., p. 26, var.

Entire fructification confluent forming a mucilaginous mass, porose. Pores ample, angulate, at length radiate-dentate. Spores as in the preceding. Plasmodium yellow.

Of these two species Fries remarks: "... Duæ sunt distinctissimæ, inter has vero longa formarum intermediarum series." Famintzin and Woronin not only concur, but consider it were more fitting to place the present species in a distinct genus, as Polyporus is set off from Hydnum. A species based upon the color of the vegetative phase only, unconfirmed by any subsequent differential character in the fruit would seem somewhat hazardous. The color of the plasmodium is incident probably to varied nutrient environment. Pores, however, are usually in evidence.

Iowa, Tennessee, Missouri, etc.; probably common everywhere.

Sub-Class MYXOGASTRES (Fries) Macbr.

1829. Sub-order Myxogastres Fries, Syst. Myc., III., p. 67.

1833. Sub-order Myxomycetes Link, Handb. der Gew., 3, p. 405.

1833. Sub-order Myxomycetes Wallroth, Fl. Crypt., II., p. 333, in part.

1858. Class Mycetozoa DeBary, Bot. Zeitung, 1858, pp. 357–365, in part.

1889. Class Myxogastres Schroeter, Engl. u. Prantl, Nat. Pflanz., I., i., p. 16.

1892. Class Myxogastres (Fries) Massee, Monograph, p. 28.

1894. Class Mycetozoa Lister, Mycetozoa, p. 21, in part.

Except as just described, the slime-moulds present abundant, minute, unicellular spores, enclosed in sporangia more or less perfectly defined, and attended by peculiar thread-like structures, free or variously attached and conjoined, the so-called capillitium.

So far as known, the spores on germination give rise to zoöspores, at first amœboid, later ciliate, again amœboid, conjugating in pairs, then, in some cases, at least, coalescing and dividing indefinitely to form the plasmodial or vegetative phase.[17]

Key to the Orders of the Myxogastres

Spore-mass black or violaceous, rarely ferruginousSeries A

Spore-mass never black; usually some shade of brown or yellow, rarely purplish or rosy, etc.Series B

Series A

1. Capillitium present, delicate, thread-like; sporangia calcareous more or less throughoutI. Physarales

2. Capillitium present, thread-like, arising usually as anastomosing branches from a well-developed columella, which in a single genus contains lime; sporangia otherwise non-calcareousII. Stemonitales

Series B

3. Capillitium none, or very imperfectly developed; spores of some shade of brown, rarely purplishIII. Cribrariales

4. Capillitium the inwardly produced irregular extremities of plates or tubules, which by their interweaving outwardly make up the aethalial wall; spores pale, ashenIV. Lycogalales

5. Capillitium made up of more or less distinctly sculptured threads, parietal or free, simple, branched, or reticulate; spores commonly yellowV. Trichiales

This sequence is meant to convey the idea that the presence of lime is indicative of differentiation less complete. That the plasmodium should at the outset eliminate, by refusing the unnecessary lime, is indicative of higher rank than that the lime should be carried until the last and then be crystallized out, or excreted by simple desiccation. The circumstance that the excreted lime may sometimes serve a protective purpose in the fruit, does not vitiate the general principle. In Series B the differentiation reaches a climax in the sculptured capillitium of the trichias.

ORDER I

PHYSARALES

Spores violaceous-black. The capillitium usually delicate and thread-like; peridium and capillitium, one or other or both, more or less extensively surcharged with lime. Peridium simple or double. Fructification various.

This order is recognizable by several characteristics, but is especially marked by the peculiar calcareous deposits which affect the capillitium or peridium, now one, now the other, more often both.

As here defined, the order Physarales includes two distinct families; of the one Physarum, of the other Didymium, is type.

Key to the Families of the Order Physarales

A. Fructification often calcareous throughout; capillitium intricatePhysaraceae

B. Calcareous deposits, when present, affecting the peridium only, or sometimes the stipe, in the typical genus plainly crystalline; capillitium simpleDidymiaceae

A. PHYSARACEÆ

Key to the Genera of the Physaraceæ

A. Fructification æthalioid1. Fuligo

B. Fructification plasmodiocarpous or of distinct sporangia.

a. Peridium evidently calcareous.

i. Capillitium calcareous throughout2. Badhamia

ii. Capillitium largely hyaline.

O Sporangia globose, etc.; dehiscence irregular3. Physarum

OO Sporangia vasiform or more or less tubular

+ Dehiscence by a lid or more or less circumscissile4. Craterium

++ Dehiscence irregular, peridium introverted5. Physarella

b. Peridium apparently limeless, at least outside.

i. Plasmodiocarpous6. Cienkowskia

ii. Sporangia distinct7. Leocarpus

C. Extra-limital.

a. Sporangia stipitate, saucer-shaped, following No. 3.Trichamphora

b. Sporangia elongate allantoid, etc., following No. 1.Erionema

1. Fuligo (Haller) Pers.

1753. Mucor Linn., Sp. Pl. II., No. 1656 (?).

1768. Fuligo Haller, Hist. Helv., Nos. 1233–1235, in part.

1801. Fuligo Haller, Pers. Syn., p. 159.

1809. Æthalium Link, Diss., I, p. 42.

1829. Æthalium Fries, Sym. Myc., III., p. 92.

Sporangia undefined, obscurely woven in and out among each other forming usually a cushion-shaped æthalioid mass. The outer layer sterile, often calcareous, forming a fragile crust, more or less defined. The middle layer sporiferous with calcigerous capillitium. The lowest layer a membranous hypothallus.

The identity of this genus seems to have been recognized first by Haller, op. cit., but by Persoon more closely defined and illustrated. Link simply translated the name into Greek, for reasons less evident now, and in this was followed by Fries. Haller's designation is now probably securely fixed.

The sporigerous median structure of the fructifications, under whatever specific name or names, is entirely confused. Sporangial walls, if ever such there were, are hardly as such recoverable, seemingly indicated only, in the changes to which the æthalium submits as in the ripening the sporogenic plasm passes on to spores.

In the present state of our knowledge the forms of this genus present withal a most perplexing problem. Are they simply phases of a single species, or are they in style and in structure sufficiently constant in their admitted variety, to claim specific rank and separate description?

To follow the example of Greville and recognize in all the literature of two hundred years varied descriptions of a single type,—this were perhaps the easier and speedier disposal of the case. Fries thought so to treat the problem but was unable to keep faith with his own decision; for no sooner he states the genus monotypic than he proceeds forthwith to offer four varieties, a. b. c. d., viz. those by Persoon and others duly recognized as species.

Recent students all, however, seem to find convenience in specific division. All seem disposed to honor Dr. Peck's Fuligo ochracea whether or not by the name he gave; and of other varieties some seem impressed by the constancy of one, some of another characteristic, thus indicating that to careful observers all over the world there are differences that may be recognized, that have been recognized again and again. If there are two species there are certainly more. Out of the gatherings of many years one may set in order not less than five variations in the fruiting of Fuligo, five distinct types of fructification, to all appearing sufficiently constant for specific recognition.

It will be said, has been said, was said by Fries, that these variations are insignificant, "pendent ex æris constitutione"; but as a matter of fact the several types now in question may be found on the same day, so that evidently something other than the atmospheric environment must determine.

Again it is said that the differences are in external form or color only, the spores in all cases almost if not quite the same. This is true; but specific characters are surface characters in fact: a species morphologically is merely the form in which a kind or genus presents itself. If the presentation be constant, for our convenience we say so, in bestowing a name. Whether in our present treatment the convenience is purely personal, students may decide.

However it all may be, there are in this part of the world many varying presentations of Fuligo capable of illustration and description; the same forms, perhaps, which have attracted the notice of the more acute mycologists in the older history of the subject. Some of these forms we here venture to describe, with such annotation as may show something of present knowledge.

Key to the Species of Fuligo

A. Æthalium 1 cm. or less; spores spherical1. F. muscorum

B. Æthalium larger, or plasmodiocarpous, even sporangi-form, crust white, smooth, even, spores elliptical2. F. cinerea

C. Æthalia larger, 2 cm. or more.

1. Cortex yellow, etc., not white; spores 6–8 µ3. F. septica

2. Cortex nearly or quite wanting; spores 10–124. F. intermedia

3. Cortex white, a foamy crust; spores 15–255. F. megaspora

1. Fuligo muscorum Alb. & Schw.

1894. Fuligo muscorum, Alb. & Schw. Lister, Mycetozoa, p. 67.

1875. Licea ochracea Peck, N. Y. Rep., XVIII., p. 55.

1879. Fuligo ochracea Peck, N. Y. Rep., XXXI., p. 56.

1894. Fuligo muscorum, Alb. & Schw., Lister, Mycetozoa, p. 67.

1911. Fuligo muscorum Alb. & Schw., Lister, Mycetozoa, 2nd ed., p. 87.

Plasmodium orange-yellow. Æthalium globoid, very small, 1 cm. or less, the cortex very thin, greenish yellow; sporangial walls not evident; capillitium well-developed, the numerous calcareous nodes fusiform or often branching, and connected by rather short, transparent internodes; spores coarsely warted, 10–11 µ.

This form seems to differ from F. septica chiefly in its constant diminutive habit of fruiting, in its delicate cortex, and in its spores, brighter, larger, and more coarsely warted. The descriptions and figure by Schweinitz seem referable to nothing else. First reported by Albertini and Schweinitz from Germany; by Schweinitz from the Carolinas; then by Dr. Peck described as a Licea from New York. It seems less commonly collected in the United States.

2. Fuligo cinerea (Schw.) Morg.

Plate X., Figs. 3, 3 a, and 3 b, and Plate XXIII.

1831. Enteridium cinereum Schw., N. A. F., No. 2365.

1875. Physarum ellipsosporum Rost., Mon. App., p. 10.

1884. Æthaliopsis stercoriformis Zopf., Pilzthiere, p. 150.

1894. Fuligo ellipsospora Lister, Mycetozoa, p. 67.

1896. Fuligo cinerea (Schw.) Morg., Cin. Soc. Nat. Hist., p. 105.

1899. Physarum ellipsosporum Rost., Macbr. N. A. S., p. 27.

1911. Fuligo cinerea Morg., List., Mycetozoa, 2nd ed., p. 88.

Plasmodium milk-white, watery. Plasmodiocarp long and widely effused, anon winding, here and there reticulate, always applanate; sometimes in form an æthalium, the peridial cortex membranous, firm, thick, and white. Capillitium well-developed, furnished with lime. Spores thin-walled, ellipsoidal, violaceous, plicate-rugose, 14–16 x 11–12 µ.

Not common. Found occasionally in shaded situations on piles of rotting straw or in the woods, especially on detritus of the bracken. The spores are many of them ellipsoidal; some are spherical; all are decidedly spinulose, perhaps might appear plicate-rugulose when dry or shrunken. Calcareous nodules very large and irregular, white.

Schweinitz, loc. cit., described this form as Enteridium cinereum. Rostafinski referred it to the genus Physarum, but was obliged to adopt also a new specific name, as that suggested by Schweinitz was already in use in the genus Physarum. Zopf, Die Pilzthiere, p. 149, founds a new genus on what seems to be the same form as here considered. This he publishes as Æthaliopsis stercoriformis Z. Massee regards the specimens discovered by Zopf as belonging to the genus Fuligo, and Lister regards Rostafinski's type as Fuligo, and includes Zopf's material under the Rostafinskian species.

This has been described as properly an American form; Lister cites other far localities.

3. Fuligo septica (Linn.) Gmel.

1753. Mucor septicus Linn., Sp. Pl. II., No. 1656 (?).

1763. Mucor ovatus Schaeff., Fung. Bav., p. 132, Fig. 192.

1791. Fuligo septica (Linn.) Gmel., Syst. Nat., p. 1466.

1826. Fuligo varians Sommf., Fl. Lapl. Sup., p. 231.

1809. Æthalium flavum Link, Diss., I., p. 42.

1829. Æthalium septicum Fr., Syst. Myc., III., p. 93.

1875. Fuligo varians Sommf., Rost., Mon., p. 134.

1892. Fuligo varians Sommf., Macbr., Bull. Lab. Nat. Hist. Ia. II., p. 160.

1894. Fuligo septica (Linn.) Lister, Mycetozoa, p. 66.

1899. Fuligo ovata (Schaeff.) Macbr., N. A. S., p. 23.

1911. Fuligo septica Gmel., Lister, Mycetozoa, 2nd ed., p. 86.

This remarkable and universal species presents as stated many forms and phases. Of these five have been selected as representative.

1. Form a. Plasmodium yellow; cortex yellow, or orange-brown, strongly calcareous friable; form indefiniteF. ovata

2. Form b. Cortex less calcareous porose, yellowish brown, fructification definite, pulvinateF. rufa

3. Form c. Cortex smooth, persistent; fructification small, less than two inchesF. laevis

4. Form d. Plasmodium yellow; cortex none; capillitium yellow, fructification thin, sometimes wide-spreadF. flava

5. Form e. Plasmodium violaceous, dark; cortex almost none; whole mass reddish or violetF. violacea

1. Form a. Fuligo ovata (Schaeff.) Pers.

Plasmodium bright yellow; æthalium pale brown, or yellowish-ochraceous, of variable size and shape, one to many cm. in diameter, and one to two cm. thick, enclosed by a distinct calcareous crust, which varies in texture, thickness, and color; capillitium well developed but variable in color, form, and extent; spore-mass dull black, sooty; spores spherical, purplish brown, nearly smooth, 7–9 µ.

Under this name may be placed our most common form. Rising with an abundant yellowish creamy plasmodium from masses of decaying vegetation, lumber, sawdust, half buried logs, it creeps about with energy unsurpassed, coming to rest only in some position specially exposed, as the top of a log or stump, the face of a stone or post, or even the high clods of a cultivated field! The fructification is large, yellow, or at most pale ochraceous, the surface when mature extremely friable like dry foam. Bulliard figures this phase well on Plate 424, Fig. 2, and calls it Reticularia (Fuligo) hortensis, from its affecting the soils of gardens. More than thirty fructifications have appeared at one time, varying in size from one to twenty cm. in a field of potatoes, well tilled, and less than an acre in extent! Such is life's perennial exuberance on this time-worn old world of ours!

Schæffer's plate CXII represents probably the same thing. So also Bolton's plate, CXXXIV. Sowerby's Fig. 2 on plate 199, and figures 1 and 2 on Greville's plate 272 possibly also depict this form. Persoon calls this F. vaporaria because it frequents hotbeds and the like, and believes this to represent the "untuosus flavus" of Linnée, although he thinks Schæffer's specimens do not. The calcareous internal structure is white.

2. Form b, F. rufa Pers.

This type of Fuligo is very different from the preceding in form, habit, and color. In form it is much more definite, usually thick, well-rounded and with some solidity. The interior fructification is gray throughout, much less expanded than in a; in fact does not resemble a at all! The cortex is porose but firm, orange at first, but becoming tawny with age, even in the herbarium. Bulliard figures it well, plate 380, Fig. 1, and Sowerby's Fig. 1 on plate 399 is also good, as are also Greville's figure 3 on plate 272 showing the two colors referred to. Not uncommon in the forest from June till September, but far more rare than a: always well-marked, with no other forms associated.

3. Form c, F. laevis Pers.

Plate X., Fig. 2, 2 a, 2 b.

This is a still more specialized type of the group. The fructification is usually small, smooth, about an inch in diameter and sometimes nearly as thick; the cortex rusty brown, enduring, persisting often when all the sporiferous grayish mass has been distributed through chinks, or from below. The figure 2 on plate X. shows this form. This also is a forest species, is autumnal rather, but may be taken sometimes as early as July. The cortex is not at all porose or spongy, in color reddish or brown, fragile indeed, but not to the touch, in the herbarium enduring for years.

4. Form d, F. flava Pers.

This is hardly F. flava of Persoon; rather of Morgan who uses Persoon's specific designation. Persoon cites Bolton's fig. CXXXIV, which is yellow indeed but is the ordinary presentation of F. septica. The form here considered is remarkable for its delicacy; extremely thin, perhaps one layer only of overlying elongate flexuous sporangia(?), covered by the merest shadow of a cortex in the form of yellow dust, soon lost: the capillitial structure yellow throughout; occurring upon fallen logs in moist dark woods; not common.

5. Form e, F. violacea Pers.

Plasmodium (Morgan teste) dark red, or wine-colored; the æthalium thin, two or three inches wide, covered by a cortex at first dull red and very soft, at length almost wholly vanishing, so that the entire mass takes on a purple-violet tint, upper surface varied with white; capillitium rather open, the more or less inflated, large, irregular nodes joined by long, slender, delicate, transparent filaments; spores dark violet, minutely roughened, spherical, about 7.5 µ.

Ohio, Tennessee. Probably everywhere, but not distinguished from 1.

Professor Morgan, who gave the genus under consideration much attention, regarded F. violacea as a form particularly well-defined. What the value of plasmodic color as a specific character in general, and how far such character is in the present case definitive, because constant, are points yet to be determined.

4. Fuligo intermedia Macbr. n. s.

Æthalium two to three cm. in greatest diameter, .5–1 cm. thick, covered with a thin, fragile, but not calcareous, greyish or brownish cortex; the spore-mass grey or violaceous-grey, firm, not at all sooty, the sporangia intricate, their walls more or less calcareous; capillitium not conspicuous; spores globose, pale purple, slightly roughened, 10–12 µ.

This form has been repeatedly sent me from Denver, Colorado, by Professor Bethel. I have refrained from publishing it, still anxious to believe that all fuligos on the face of the earth were of one species. In the species next following it must be admitted that the spore-variations are too wide to remain comfortably under shelter of a single specific name. The present species is not F. septica, neither is it F. megaspora; it is F. intermedia.

Colorado; Iowa.

5. Fuligo megaspora Sturg.

1913. Fuligo megaspora Sturg., Col. Coll. Pub., p. 443.

Æthalium pulvinate one to three inches in diameter, covered with a thick spongy incrustation of lime, white or yellowish toward the base: sporangia convolute, the walls membranous, brittle, charged throughout with round white granules of lime, 1.5–2 µ in diameter: columella none: capillitium of delicate, colorless, anastomosing tubules, bearing toward the center large, white, branching calcareous nodules; spores spherical, or somewhat oval, dark purple-brown, rough-tuberculate, 15–20 µ.

This species differs as pointed out by Professor Sturgis, chiefly in the character of the spores, their unusual size and roughness.[18]

Colorado; Africa!—Robert Fries.

EXTRA-LIMITAL

Erionema Penzig

1898. Erionema Penzig, Die Myx. d. Fl. v. Beutenzorg, p. 36.

Sporangia plasmodiocarpous but distinct, cylindrical; capillitium intricate, elastic; nodules few.

1. Erionema aureum Penzig

1898. Erionema aureum Penz. l. c.

Sporangia elongate, clustered, pendulous, yellow or grayish yellow, generally stipitate on long flaccid stalks, or sessile and interlacing: stipes yellow, blending with the hypothallus; capillitium intricate, expanding at maturity after the manner of Arcyria to several times the sporangial length, the nodules small, yellow; spores nearly smooth, violaceous-brown, 5–6 µ.

This unique form is near the fuligos which it resembles, especially when sessile, in its intricate sporangia. The spores also are those of the common Fuligo septica. The habit is however entirely different. Mr. Fetch describes clusters in Ceylon, hanging free, four to six cm. in length!

2. Badhamia (Berkeley) Rost.

1852. Badhamia Berkeley, Trans. Linn. Soc., XXI., p. 153.

1875. Badhamia Rostafinski, Monograph, p. 139.

Sporangia simple; peridial wall simple, thin, breaking irregularly; capillitium formed of abundant, richly anastomosing tubules, filled throughout their entire length with calcareous granules; the nodes often feebly represented; stipe poorly developed or wanting entirely; columella, except in forms sometimes assigned to the sub-genus Scyphium, poorly developed or none; spores frequently adherent in clusters.

The whole genus calls for careful and protracted study; and the present so-called species are like something new on the world; as full of vagaries as though but just entered upon their phylogenetic race.

This genus is closely related to Physarum, but differs in having the capillitium calcareous throughout. Forms occur and are included here, in which the capillitium, especially in some parts, is physarum-like, physaroid. Nevertheless, the distinctions hold good as a rule, and are at once diagnostic.

In capillitial differentiation the badhamias are definite and beautiful. The net in a typical species, as B. papaveracea, is throughout uniformly evenly tubular, the calcareous deposits delicate in the extreme, presenting, as the spores disappear, an elegant trabecular structure as if to support the persisting peridium if not the original content. In other forms the capillitium is physaroid, with swollen nodes, but heavily calcareous but not quite throughout. Badhamia, Physarum, Tilmadoche, Craterium present a consistent group, of which Physarum is the generalized expression.

Berkeley's idea of the genus was expressed as follows: "Peridium naked or furfuraceous. Spores in groups, enclosed, at first, in a hyaline sack." Rostafinski, while accepting Berkeley's generic name, redefined it, emphasized the calcareous capillitium, and made reference to the spore-adherence only to assert that Berkeley's description was, in this particular, based on mistaken observation. In some species, the spores do, in fact, show a tendency to cling together, a characteristic which Badham was perhaps first to notice; but that this is occasioned by their being surrounded by a sac or common pellicle has not been proved nor even suggested, by any subsequent investigator. Berkeley's genus was therefore founded upon a slight mistake; but we may conserve his rights in the premises if we write Badhamia (Berk.) Rost., and so keep history straight.

Key to the Species of Badhamia

A. Spores ovoid or ellipsoidal

a. Spores free1. B. ovispora

b. Spores adherent2. B. versicolor

B. Spores spherical

a. Sporangia yellow

i. Spores free3. B. decipiens

ii. Spores adhering4. B. nitens

b. Sporangia grey, spores free

i. Always sessile5. B. panicea

ii. Stalked, at least some of them

O Stipe when present black

+ Globose, small .5 mm.6. B. affinis

++ Larger, spores strongly spinulose7. B. macrocarpa

+++ Discoidal or annulate8. B. orbiculata

OO Stipes membranous yellowish

+ Stipes long, sporangia iridescent9. B. magna

++ Stipes short or none; iridescent10. B. foliicola

c. Sporangia grey, spores adherent

i. Stipe when present yellowish

+ Wall iridescent, spores uniformly marked11. B. utricularis

++ More calcareous, spores strongly marked on one side12. B. capsulifera

+++ Colorado, spores anon barred13. B. populina

ii. Stipe when present black14. B. papaveracea

d. Sporangia brown, lilacine

i. Sessile15. B. lilacina

ii. Stipitate, columellate16. B. rubiginosa

1. Badhamia ovispora Racib.

1884. Badhamia ovispora Racib., Myx. Ag. Cracov., XII., p. 72.

Sporangia sessile depressed-globose or plasmodiocarpous, white or ochraceous, covered by dense calcareous scales; capillitium white, the lime-granules sometimes aggregate at the center to form a pseudo-columella; spores not adhering, brownish-purple ellipsoidal, 8 × 10–10 x 15 µ.

Reported from Bohemia, England, Pennsylvania.

2. Badhamia versicolor Lister.

1901. Badhamia versicolor List., Jour. Bot., XXXIX., p. 81.

1911. Badhamia versicolor List., Mycetozoa 2nd ed., p. 35.

Sporangia scattered or clustered, minute, .3–.5 mm., grey or flesh-colored, sessile, the calcareous deposits slight; capillitium white or apricot-colored; spores ovoid, 8 × 10–9 × 12 µ, clustered, purplish, and warted at the broader end, elsewhere colorless and smooth.

This little species, as it comes to us, is grey, very uneven in size, .2–.5 mm. and generally irregular in form and habit, perhaps scarce mature. The capillitium is white, physaroid. The spores furnish the distinguishing character. Sometimes globose, about 9–10. They are most of them definitely and permanently affected in shape by the fact of cluster-association, narrower in the direction of the cluster center. The indications are that these may become globose with maturity.

Colorado,—Bethel; Scotland.

3. Badhamia decipiens (Curtis) Berk.

1848. Physarum decipiens Curtis, Am. Jour. Sci., VI., p. 352.

1873. Badhamia decipiens Berk., Grev., II., p. 66.

1873. Physarum chrysotrichum Berk. & C., Grev. II., p. 66.

1876. Badhamia chrysotricha (Berk. & C.) Rost., App., p. 4.

Sporangia gregarious, depressed-spherical or ovate, sessile, occasionally plasmodiocarpous, dull yellow, roughened by the rather large numerous calcareous scales; columella none; capillitium dull orange, strongly calcareous, only slightly widened at the nodes; spore-mass black; spores pale violet, minutely spinulose, free, 10–12 µ.

Among badhamias this and the next species are at once distinguished by the color. If the brief description (Grev., II., p. 66) can be regarded as defining anything, this is the same as P. chrysotrichum Berk. & C. It resembles somewhat P. serpula Morg., but differs externally in color and in the surface scales, which are not perceptible in the Physarum. The present species also resembles Cienkowskia reticulata (Schw.) Rost., but has a different capillitium. See under that species.

Chiefly eastern and American. New England, Pennsylvania, Ohio, South Carolina; reported recently also from Sweden and Germany.

4. Badhamia nitens Berk.

1852. Badhamia nitens Berk., Trans. Linn. Soc., XXI., p. 153.

1863. Badhamia inaurata Currey, Trans. Linn. Soc., XXIV., p. 156.

1873. Badhamia nitens Berk., Rost., Mon. App., p. 3.

Sporangia gregarious or closely crowded, globose or depressed-globose, .5–1 mm. in diameter, yellow or greenish yellow, rugulose, sessile; capillitium yellow, forming an open net with occasional thickenings at the nodes; spores clustered, delicately roughened, violaceous-brown, 10–12 µ.

This much resembles the preceding species except in the clustered spores, and more commonly aggregate habit. The spores, as usual when clustered, are conspicuously echinulate on the outer side. This did not escape the notice of the author of the species, op. cit.

Colorado, Oregon. Reported from West Indies, Ceylon, various parts of Europe.

5. Badhamia panicea (Fries) Rost.

1829. Physarum paniceum Fries, Syst. Myc., III., p. 141.

1873. Badhamia panicea (Fr.) Rost., Fuckel, Sym. Myc. Nachtr., 2, p. 71.

Sporangia gregarious or aggregated in closely compacted clusters, globose or hemispherical, sessile, the peridium thin, transparent, thickly dotted with white calcareous scales; stipe none; columella none, although a pseudo-columella sometimes appears, formed by a more dense development of the capillitium near the centre of the sporangium below; capillitium abundantly developed, quite uniformly thickened, but showing an occasional delicate connecting thread, the nodes also somewhat flattened and enlarged; spore-mass black; spores by transmitted light, bright violaceous-brown, minutely roughened, 10–13 µ. Plasmodium is said to be white.

In America this seems to be a purely western species. Specimens are before us from western Iowa and from Colorado, South Dakota, Nevada, and Southern California. It is very well marked, though liable perhaps to be mistaken at first sight for sessile phases of P. notabile or P. cinereum. The capillitium is, however, at once determinative. Colorado; Bethel. Europe generally.

6. Badhamia affinis Rost.

1875. Badhamia affinis Rost., Mon., p. 143.

Sporangia aggregated, cespitose and sessile, or sometimes stipitate, depressed above, flat or umbilicate below, the wall grayish white, rugulose, and more or less calcareous-scaly; the stipe when present erect or sometimes nodding, black or brownish black; hypothallus scanty; columella none; capillitium not abundant, white, the nodes somewhat expanded; spores globose, minutely roughened, violet-brown, large, 16–17 µ.

Chiefly on moss, the pale ashen sporangia generally very small, mounted on the tips of the leaves, sometimes sessile, sometimes with a distinct black stipe in which case the peridium is distinctly umbilicate. Specimens from Kansas referred here have the stipe pale, rugose, long, about twice the sporangium; habitat bark.

Rare. New York, Ohio, Kansas; more recently reported from Scotland and Japan.

There is nothing new to be added here; nor appears any other place to which such material as we have may be referred. New collections no doubt will one day appear, when the identity may, let us hope, be made secure.

Meantime we have a form closely related which may be entered as

Badhamia iowensis Macbr. n. s.

Sporangia gregarious or loosely scattered, depressed globose, .4–.6 mm. in diameter, stipitate, grey, flecked by rather prominent but small rounded calcareous scales: the stipe short, half the diameter of the sporangium, black or very dark brown, without hypothallus but widening above into a shallow expanded base for the sporangia; columella none: capillitium dull yellow, sometimes white, strongly calcareous, physaroid, heavy; spores free, dark brown in mass, pale violet by transmitted light, minutely verruculose, the tiny warts in some areas more densely placed, producing evident shadowy spots, 10–11 µ.

This interesting little species occurs on the lower surface of fallen logs, blocks, etc., in colonies of considerable extent, hundreds of sporangia in a place. The capillitium is comparable to that of B. decipiens or B. panicea; it is physaroid to the extent that an occasional filament may be found non-calcic, and not typically badhamioid as in B. papaveracea, B. macrocarpa. The sporangial base persists, dark brown, bearing traces of the clumsy capillitium, but no columella real or simulated. Blackhawk Co., Iowa; communicavit Dr. Jessie Parish. See Plate XX., 1, 1 a, 1 b.

Reddish or roseate forms sometimes appear in colonies otherwise as described. It differs from B. affinis in the size and character of the spores, in color and character of the capillitium, habit and surface markings.

7. Badhamia macrocarpa (Ces.) Rost.

1855. Physarum macrocarpon Cesati, Flora, XXXVIII., p. 271.

1875. Badhamia macrocarpa (Ces.) Rost., Mon., p. 143.

Sporangia scattered or closely aggregate, crowded globose or sub-globose, generally sessile, rugulose, white; the peridium membranous, white above, below yellowish or brown; capillitium not abundant, thoroughly calcareous, the nodes broad, conspicuous, the connecting tubules rigid; columella none; hypothallus scant or none; spore-mass black, spores non-adherent, by transmitted light bright clear brown, thickly spinulose all over, large spherical, 12–15 µ.

Closely resembles externally B. panicea, but is easily distinguished by larger and remarkably spinulose spores, in this particular unrivalled in the entire genus. European authors describe both sessile and stipitate forms. American specimens generally are sessile and for the most part closely crowded, almost heaped; but—Prof. Bethel finds this in winter everywhere on fallen rotting stems of Opuntia and on the bases of dead Yucca leaves, still attached. Associated with the typical phase and often occurring alone on the Yucca leaves is a discoidal form which when first sent in (1908) was called var. gracilis. Presented alone to one ignorant of its history and associations, it would surely pass for a distinct species. This stalked phase is very delicate; the stipe pale brown, or yellow. See Plate II., Fig. 9. See also Sturgis Col. Coll. Pub. XII., 408.

8. Badhamia orbiculata Rex.

Plate XIV., Fig. 4.

1893. Badhamia orbiculata Rex. Proc. Phil. Acad., p. 372.

1894. Badhamia macrocarpa Rost., Lister, Mycetozoa, p. 34 (in part).

1911. Badhamia orbiculata Rex., Lister, Mycetozoa, 2nd ed., p. 37

Sporangia stipitate or sessile, orbicular discoidal, irregularly elongated or plasmodiocarpous, averaging about 1 mm. in width, generally stipitate, and when stipitate, flattened or depressed above, plane or slightly umbilicate below; the peridium simple, more or less translucent from the varying number of innate granules, sometimes covered with circular flat masses of lime, gray except the point of attachment to the stipe which is brown; stipe short, black, rough, plicate; capillitium dense at the centre, radiant at the periphery where it meets the sporangial wall, white; spores violaceous black, minutely warted, 12–15 µ.

This is a beautiful species, easily known by its discoidal or almost annulate sporangia mounted upon short dark black stipes. The stipe in western collections is sometimes very short, but generally suffices to raise the sporangium, a little at least, above the substratum. Sessile and plasmodiocarpous forms do occur with the typical stipitate phase, but may be regarded here as elsewhere as indicative of incomplete development. Plasmodium cream-colored, or pale yellow.

Pennsylvania, Ohio, Iowa, Nebraska, South Dakota, Colorado.

9. Badhamia magna Peck.

Plate XIV., Fig. 1.

1871. Dictydium magnum Peck, Rep. N. Y. State Mus., XXIV., p. 84.

1879. Badhamia magna Peck, Rep. N. Y. State Mus., XXXI., p. 56.

1894. Badhamia macrocarpa Rost., Lister, Mycetozoa, p. 34, in part.

1892. Bahamia varia Mass. Mon. Myxog., p. 319, in part.

1894. Badhamia magna Peck, List., Mycetozoa, p. 33.

1899. Badhamia capsulifera (Berk.) Macbr., N. A. S., p. 68.

1911. Badhamia magna Peck, Lister, Mycetozoa, 2nd ed., p. 34.

Sporangia globose or ellipsoid, .7–1 mm., pale iridescent, stipitate; peridium thin with slight calcareous deposits, rugulose, opening irregularly, white; stipe long flaccid, straw-colored; capillitium an elegant uniform net, its threads stiffened by slight deposits of lime, the nodes little thickened, badhamioid; spores free, dusky with a shade of violet, minutely spinulose, about 10 µ.

This beautiful species closely resembles some forms of B. utricularis from which it differs chiefly in its unclustered smooth spores. B. foliicola as recognized here is hardly more than a smaller, short-stemmed form of this; see species next following.

Not rare in the eastern United States and Canada; Iowa. Seems to take the place of B. capsulifera of Europe.

10. Badhamia foliicola Lister.

1897. Badhamia foliicola List., Jour. Bot., XXXV., p. 209.

1911. Badhamia foliicola List., Mycetozoa, 2nd ed., p. 34.

"Plasmodium orange." Sporangia smaller, about .5–.6 mm., globose or ellipsoidal, iridescent-gray, stipitate or sessile, the peridium thin, rugulose, sparingly calcareous, when empty white; the stipe when present short but yellowish, of the flaccid sort; capillitium badhamioid; spores free, delicately spinulescent, dusky-violaceous, about 12–13 µ.

This has been so far collected but once, on the shores of Lake Okoboji. It was developed, no doubt, on the natural débris of a bur-oak prairie border, and went to fruit on the leaves, stems, and fruiting spikes of a species of Setaria. It may prove to be different from the B. foliicola of Europe; future collections and study must reveal that. Meantime it seems wise to refer it here.

The color of the plasmodium is quoted from Miss Lister; a fact of some importance only when constant and confirmed by other criteria.

Iowa; Toronto,—Miss Currie.

11. Badhamia utricularis (Bull.) Berk.

1791. Sphaerocarpus utricularis Bull., Champ., p. 128, t. 417, Fig. 1.

1826. Physarum utriculare Chev., Fl. Paris, I., p. 337.

1829. Physarum utriculare Fries, Syst. Myc., III., p. 139.

1852. Badhamia utricularis (Bull.) Berk., Tr. Linn. Soc., XXI., p. 153.

Sporangia clustered, spherical or ovoid, large, sessile or mounted on long, thin, strand-like stalks, blue-gray, violet-iridescent or cinereous, smooth or more often rugulose; the stipes when present poorly differentiated, as if thread-like filaments and strips of the plasmodium, often branched and always reclining or even prostrate; hypothallus none; capillitium a large-meshed open network of rather slender tubules, the nodes unequally developed, white with the enclosed lime; spores not strictly adherent though not without some tendency to stick together, delicately warted, bright violet-brown, 10–12 µ.

This species resembles B. capsulifera, but is distinguished by a more strongly rugulose less calcareous peridium and a more profuse development of filamentous stipes, but especially by the character of the spores. The spores of the present species while inclined, when mounted in a liquid, to stay together, nevertheless do not coalesce in heaps as in the related species, nor do they show any differentiation in the episporic markings, these being uniform over the entire spore.

This is one of the finest and perhaps the most beautiful species of this fine genus. It is a forest species, generally to be found on trunks of fallen Populus or Tilia where the fine soft gray colonies often spread for several inches along the ridges and in crevices of the bark.

Colorado (Bethel); Mississippi valley and east.

12. Badhamia capsulifera (Bull.) Berkeley.

1791. Sphaerocarpus capsulifer Bull., Champ., p. 139, t. 470, Fig. 2.

1801. Physarum hyalinum Pers., Syn. Meth. Fung., p. 170.

1852. Badhamia capsulifera Berk., Tr. Lin. Soc., XXI., p. 153.

1852. Badhamia hyalina Berk., Tr. Lin. Soc., XXI., p. 153.

1875. Badhamia hyalina (Pers.) Rost., Mon., p. 139.

1875. Badhamia capsulifera (Bull.) Rost., Mon., p. 141.

1894. Badhamia hyalina Lister, Mycetozoa, p. 30.

1911. Badhamia capsulifera Lister, Mycetozoa, 2nd ed., p. 31.

Sporangia clustered or gregarious, sessile or sometimes stipitate, globose or obovoid, gray or greenish white, snow-white when empty; the peridium thin, translucent; the stipe, when present, as in B. utricularis, although generally shorter and better developed, yellow or straw colored; capillitium a very loose, open network of white, lime-filled tubules, not much expanded at the nodes; columella none; spore-mass purplish-brown; spores adhering in clusters of five or six to twenty or more, globose, but affected somewhat by mutual pressure, rough throughout, the exposed surface in the cluster, more distinctly warted, 10–12 µ.

This is Badhamia hyalina (Pers.) Berk., Rost., Mon., p. 139; but Rostafinski himself admits that the two species, here united, as he defined them, are very much alike, having "the same spores and capillitium", differing in the form of the sporangium, an inconstant feature. Bulliard's name has precedence; his descriptions of this and the preceding species are remarkable.

The peculiarly adherent spores distinguish the species from B. utricularis; and the sporangia sessile or with short but strand-like stipes, distinguish it from B. papaveracea.

The description above is for the typical European form. Lister expresses doubt whether this occurs in the United States. The form from Iowa which is the basis for the inclusion of the species in N. A. S. is, we believe, nothing else than B. capsulifera (Bull.) Berk. The form approaches B. populina as this is presented in Colorado. The Iowa specimens are white, aggregate, superimposed, etc., but have the capillitium and spores exactly as described for the type. Accordingly B. populina as this occurs in Colorado has been for years referred to the Berkeley species. The thicker more strongly calcareous peridia constitute, as would appear, the principal difference in the forms from Colorado. See next species.

13. Badhamia populina List.

1904. Badhamia populina List. Jour. Bot., XLII., p. 129.

1911. Badhamia populina List. Mycetozoa, 2nd ed., p. 32.

Plasmodium white; sporangia sessile, crowded, heaped, large, 1.5 mm., rarely stipitate, globose or ovoid, white; stipe when present brown; capillitial strands broad, calcareous; spores clustered, 16–20 in a cluster, purple-brown, roughened and sometimes marked by obscure ridges and bands, 10–12 µ.

Generally distinguishable by its unusually large calcareous, white sporangia. The peridia are strongly calcareous, shell-like in texture. In some cases the color is tinted with rose.

This species is very near B. capsulifera as recognized in the United States. When white the Colorado material corresponds almost exactly with the forms collected in Iowa, and regarded as representing the species just named. The Colorado gatherings are more strongly calcareous and the spores sometimes present the variations named. "The Colorado phase of the American form."

Colorado,—Bethel. Europe?

14. Badhamia papaveracea Berk. & Rav.

Plate IX., Figs. 6, 6a, and 6b.

1873. Badhamia papaveracea Berk. & Rav., Grev., II., p. 66.

1894. Badhamia hyalina var. papaveracea Lister, Mycetozoa, p. 30.

1899. Badhamia papaveracea Berk. & Rav., Macbr., N. A. S., p. 69.

1911. Badhamia papaveracea Berk. & Rav., List., Mycetozoa, 2nd ed., p. 32.

Sporangia gregarious, globose, large, stipitate, iridescent-gray; the peridium thin, translucent, and containing but little calcareous deposits, smooth or slightly rugulose; stipe very short, but generally distinct, black or very dark brown; hypothallus none; capillitium a network of large meshes with expanded nodes, prominent, white, persistent after the spores have been blown away; spore-mass deep brown; spores adherent as in B. capsulifera, marked in much the same way, and about the same size, 10–12.5 µ

Distinguished by its short, dark, stipe and adherent spores.

Not common. New England, Pennsylvania, Ohio, Maryland, South Carolina, Wisconsin, Iowa.

15. Badhamia lilacina (Fries) Rost.

1829. Physarum lilacinum Fries, Syst. Myc., III., p. 141.

1875. Badhamia lilacina (Fries) Rost., Mon., p. 145.

1892. Craterium lilacinum Mass., Mon., p. 271.

1894. Badhamia lilacina (Fr.) Rost., Lister, Mycetozoa, p. 34.

1911. Badhamia lilacina (Fr.) Rost., List., Mycetozoa, 2nd ed., p. 38.

Sporangia globose, sub-globose, or obconical, sessile, gregarious or more or less clustered, supported by a thin, continuous, transparent hypothallus; the peridium smooth pale, lilac-brown without, white within; stipe none, although some sporangia have a narrowed base; columella none, the pseudo-columella formed by a more densely aggregated capillitium near the base; capillitium dense, white, strongly nodulose; spore-mass black; spores dark, violaceous-brown by transmitted light, distinctly warted, or reticulate, the reticulations resembling somewhat those of some of the trichias, as T. affinis, 10–15 µ.

Easily recognizable, generally at sight, by its peculiar color. White forms, however, occur; often lilac-tinted and white from the same plasmodium. A perfectly white colony seems to be rare. Both colors are shown in specimens distributed. N. A. F., 2494.

Common eastward, Ontario, New England, Pennsylvania, Ohio, etc. Not reported west of the Mississippi River.

Whatever the color, the spores are in every case positively diagnostic. The episporic markings are unlike those of any other species in the present order. Dr. Rex describes some New York forms as provided with a short but distinct stipe. Such forms resemble externally Scyphium rubiginosum (Chev.) Rost. The hypothallus is also unique. V. next species.

16. Badhamia rubiginosa (Chev.) Rost.

Plate X., Figs. 1, 1a, 1b, 1c.

1826. Physarum rubiginosum Chev., Fl. Par., p. 338.

1872. Craterium obovatum Peck, Rep. N. Y. Mus., XXVI., p. 75.

1875. Scyphium rubiginosum (Chev.) Rost., Mon., p. 148.

1876. Badhamia rubiginosa (Chev.) Rost., Mon. App., p. 5.

1892. Craterium rubiginosum Massee, Mon., p. 270.

Sporangia gregarious, obovoid, grayish brown, stipitate, the peridium simple, membranous, above thin, pale, more or less calcareous below, more persistent blending with the stipe; stipe erect, reddish brown or purplish, expanded below into a small hypothallus, above, prolonged within the sporangia more than half its height as a definite columella; capillitium very dense, snow white, long persistent with the lower two-thirds of the sporangial wall; spore-mass dark brown; spores by transmitted light, dark violet or purple-brown, minutely roughened or spinulose, not adherent, 12–14 µ.

This is probably the most common badhamia in the country and in the world. It is found every year, in the woods, on masses of decaying leaves, especially those of various species of oak. The plasmodium is yellow. The fructifications are very distinct, not likely to be mistaken for those of any other species; the stipes constitute a very prominent feature in every gathering I have seen. Sometimes these are more or less coalescent, especially toward the base, where they are apt to be also wrinkled or longitudinally striate; in other specimens the stipes are well differentiated, long, terete, with little or no hypothallus.

Badhamia curtisii (Berk.) Rost. is according to Lister (Mon., p. 35) a sessile phase of this species. The only specimens known are in the herbarium of Berkeley, now at Kew. The species is based upon a gathering from S. Carolina. Berkeley thought it a didymium, called it D. curtisii.

Reported from western Europe; the typical form abundant in the forested regions of eastern N. America, especially in the Mississippi valley.

17. Badhamia subaquila Macbr.

1899. Badhamia subaquila Macbr., N. A. S., p. 64.

Sporangia closely gregarious or crowded, globose or sub-globose, sessile, brown, the peridium a thin but persistent brown membrane, rupturing above irregularly and remaining as a cup after spore dispersal; hypothallus none; capillitium strongly developed, thoroughly calcareous, the meshes large, the nodular thickenings broad, white; spores globose, in mass black, by transmitted light brown, very rough-warted, large, 15–18 µ.

The variety is founded on material sent from Maine by the late Mr. F. L. Harvey. Professor Harvey, upon the authority of Mr. Morgan of Ohio, quotes the species, Bull. Tor. Bot. Club, 24, 67, as B. verna (Somm.) Rost. But the specimens certainly do not conform to description of B. verna. Here the wall corresponds with what is seen in B. rubiginosa; but the spores are much larger, and the capillitial structure very different.

Miss Lister regards this a form of No. 16. So far, the original gathering represents the species; but the woods of Maine are certain one day to send added information.

Rare. On mossy logs, Maine.

3. Physarum (Persoon) Rost.

1794.[19] Physarum Pers., Rom. Neu. Mag. f. d. Bot., I., p. 88, in part.

1795. Physarum Pers., Ust. Ann. Bot., XV., p. 5, in part.

1801. Physarum Pers., Syn. Fung., p. 168, in part.

1829. Physarum (Pers.) Fries, Syst. Myc., II., p. 127, in part.

1875. Physarum (Pers.) Rost., Mon., p. 93.

Sporangia plasmodiocarpous, æthalioid or distinct; the peridium usually simple, sometimes double, irregularly dehiscent, more or less definitely calcareous; capillitium a uniform irregular net, dilated and calcareous at the nodes, adherent on all sides to the peridial wall.

This large and cosmopolitan genus is readily recognized by the characters quoted. It may be added that the capillitial threads are always exceedingly delicate, probably tubular, but never filled with lime throughout; the peridium may be almost nude or encrusted with lime, which, where present, is always amorphous, never crystalline; the sporangia when distinct may be either sessile or stipitate, and the stipe in the latter case is often hollow and charged with lime. In capillitium intermediate between Leocarpus and Badhamia, since in the first the capillitium is unequally calcareous, diverse, while in Badhamia the capillitium is intricate and calcareous throughout.

As first set up by its founder, the genus included diverse forms, only one or two of which would be included in the genus as now limited.[20] Persoon, however, was left to develop the matter to suit himself, and in successive works gave, under this generic name, more and more prominence to forms now so referred. Fries, Syst. Myc., III., pp. 127 et seq., still better establishes the genus, though still including forms that, judging from the description, seem to belong elsewhere. Twenty years later Fries revising somewhat his earlier work thought to improve the chances of future students by reducing the number of physarums. This he would do by setting out certain evidently inter-related forms to make a new genus, Tilmadoche.

He named two or three species only, leaving his sucessors to add others as occasion offered.[21]

Rostafinski approved the good intention of Fries, but in the Monograph, he entirely re-cast the genus as constituted by Fries; actually called the species 'first cited' a typical physarum! Would not have it in the new genus at all, first or last; but instead took the second species of Fries as the type and added several forms, some from the Friesian list, to make up a respectable group.

Until quite recently writers on the subject have generally approved the course adopted by the Polish author. The arrangement showed features of convenience, even if artificial to a degree. Perhaps we gain advantage in all directions if we treat the original genus Physarum as a whole, but in the key take advantage of Fries' suggestion. We may write—

Key to the Species of Physarum

1. Capillitium irregularly reticulate throughout; calcic nodes variousPhysarum

2. Capillitium more regular, especially below, furcate; nodes fusoidTilmadoche

SECTION I. PHYSARUM

I. Fructification not stipitate, more or less plasmodiocarpous.

1. Peridium simple.

a. Calcareous deposits yellow1. P. serpula

b. Calcareous deposits reddish or orange2. P. lateritium

c. Calcareous deposits white, peridium rugulose3. P. vernum

2. Peridium double.

a. Fructification flatly compressed4. P. sinuosum

b. Fructification less compressed, rounded.

i. Outer peridium white5. P. bitectum

ii. Outer peridium brown or brown-tinged6. P. bogoriense

iii. Outer peridium yellow; capillitium yellow7. P. alpinum

II. Fructification of sporangia more or less distinct.

A. Sporangia sessile, globose, ovoid, reniform, etc.

1. Peridium double.

a. Sporangia white, peridium testaceous.8. P. diderma

b. Sporangia tinged with yellow.

i. Sporangia as if interwoven, compressed9. P. contextum

ii. Sporangia more nearly free, distinct.

o Spores pale, inner peridium brittle10. P. conglomeratum

oo Spores spinulose, dark violet11. P. mortoni

c. Sporangia brown, dehiscence revolute12. P. brunneolum

2. Peridium simple, calcareous, flaky.

a. Sporangia grey, plasmodiocarpous; spores dusky, 10–12 forms of 3

b. Sporangia grey, more or less dense; spores violet, 6–713. P. cinereum

c. Calcareous deposits yellow or greenish, spores 7–914. P. virescens

d. Sporangia rusty or reddish brown, more or less dense15. P. rubiginosum

e. Sporangia minute, lignicolous, the fructification much extended upon a hypothallus, lime deposit tawny16. P. instratum

f. Sporangia white, depressed, annulate, sometimes with short stipes17. P. megalosporum

3. Peridium simple, not flaky, small .2–.3 mm., heaped18. P. confertum

B. Sporangia, at least some of them, stipitate.

a. Sporangia columellate.

i. Columella small, usually conical.

O Sporangium yellow.

o Columella white19. P. melleum

oo Columella yellow20. P. citrinum

OO Sporangium not yellow.

o Capillitial mass persistent.

+ Sporangia globose, pallid or white21. P. globuliferum

++ Sporangia blue or lilac, rose, etc.22. P. lilacinum

+++ Sporangia drab or brownish23. P. murinum

++++ Sporangia wine-red24. P. pulcherrimum

oo Capillitial-mass less persistent; orange25. P. pulcherripes

ii. Columella long, 4–5 the sporangium non-calcareous.26. P. penetrale

iii. Columella large globose27. P. luteo-album

b. Sporangia without columella.

i. Sporangia nucleate, calcareous at center.

O Stipe yellow28. P. nucleatum

OO Stipe white29. P. wingatense

ii. Sporangia non-nucleate.

O Sporangia purple30. P. newtoni

OO Sporangia blue, spotted with red31. P. psittacinum

OOO Grey or white, iridescent betimes.

o Sporangia white, discoidal; stipe yellow32. P. discoidale

oo Sporangia lightly calcareous, iridescent, sub-globose, diam. about = to the stout, brown, slightly wrinkled stipe33. P. leucophaeum

ooo Sporangia globose or sub-globose.

x. Small, .5 mm.

+ Stipe erect, clear brown34. P. nodulosum

++ Stipe weak, yellow, stuffed35. P. maculatum

xx. Larger, lime-capped; stipe strand-like36. P. didermoides

xxx. Stipe snow-white, fragile37. P. leucopus

xxxx. Stipe generally distinctly fluted

+ Sporangia laterally compressed, fan-shaped38. P. compressum

++ Sporangia typically globose, umbilicate below, connate, etc., strongly calcareous39. P. notabile

+++ Sporangia reniform, concave below P. affine, see under 38

++++ Sporangia larger, to 1 mm., nearly limeless, iridescent40. P. tropicale

oooo Sporangia obovate, compound, clustered, the stipe fuscous, fluted, short.41. P. nicaraguense

OOOO Sporangia yellow, rarely iridescent or brown.

o Capillitial nodes white.

x. Stipe also white42. P. sulphureum

xx. Stipe flesh-colored, spores smaller43. P. carneum

xxx. Stipe red or reddish brown44. P. citrinellum

xxxx. Stipe yellowish, flaccid, sporangia leocarpine45. P. albescens

xxxxx. Stipe very short or none, sporangia cylindric, brown46. P. variabile

oo Capillitium nodes yellow or orange-yellow.

x. Badhamioid, larger,—to .8 mm.47. P. auriscalpium

xx. Physaroid, base persistent48. P. oblatum

ooo Capillitium nodes pure yellow.

x. Capillitial threads yellow49. P. galbeum

xx. Capillitial threads hyaline50. P. tenerum

xxx. Peridium iridescent.

+ Capillitium persistent51. P. flavicomum

++ Capillitium less persistent, larger52. P. bethelii

SECTION II. TILMADOCHE

I. Æthalioid, gyrose or irregular53. P. gyrosum

II. Fructification stipitate.

1. Sporangia irregular, often convolute, involved54. P. polycephalum

2. Sporangia simple, nutant, discoidal.

a. Thin-walled, grey or white.55. P. nutans

b. Vari-colored, yellow, greenish, orange, etc.56. P. viride

1. Physarum serpula Morgan.

Plate IX., Figs. 6, 6a, and 6b.

1831. Physarum reticulatum Alb. & Schw., Schweinitz, N. A. F., No. 2295.

1885. Physarum gyrosum (Rost.) Wingate, Ellis, N. A. F., No. 1396.

1892. Physarum gyrosum Rost., Massee, Mon., p. 307.

1892. Cienkowskia reticulata Rost, Macbr., Bull. Nat. Hist. Iowa, II., 2, p. 150.

1894. Badhamia decipiens Berk., Lister, Mycetozoa, p. 33, in part.

1896. Physarum serpula Morg., Cin. Soc. Nat. Hist., p. 101.

1899. Physarum serpula Morg., Macbr., N. A. S., p. 29.

1911. Physarum serpula Morg., Lister, Mycetozoa, 2nd ed., p. 81.

Plasmodiocarp repent, reticulate, forming anon lines, circles, dots, etc., venulose pale yellow, ochraceous, at length whitish, the peridium thin, membranaceous, simple, fragile, but withal persistent, below united with a hypothallus which is more or less widely produced; capillitium rather scant, but abundantly charged with polygonal nodules of lime, yellow; spore-mass black; the spores, by transmitted light, violaceous, warted, globose, 10–13 µ. Plasmodium, at maturity, greenish-yellow.

A very distinct species not likely to be confused with anything else, although in description, so far as concerns external characters, suggesting Cienkowskia reticulata. The two forms are not at all alike when placed side by side. For details as to the difference, see the description of the species last mentioned.

Apparently not rare in eastern United States, Pennsylvania, Virginia, Ohio, Iowa.

In 1805, Albertini and Schweinitz, Conspectus Fungorum, p. 251, t. 7, Fig. 2, described as Physarum reticulatum, a European form which became the basis of Rostafinski's genus Cienkowskia; see under that genus. Later, 1829, Schweinitz discovered in America a physarum-looking specimen which he took to be the same thing, and accordingly placed in his herbarium under this name, and entered N. A. F. 2295. Rostafinski further renamed another Schweinitzian species Fuligo muscorum calling it, Mon., p. 111, Physarum gyrosum. Wingate and Rex apply in Ellis, N. A. F., this latter name to No. 2295 of Schweinitz. Such a reference is a mistake, judging from Rostafinski's descriptions and from the description and figure of Albertini and Schweinitz (Consp. Fung., p. 86, t. 7, I), and by the testimony of Lister. For further concerning Rostafinski's species, see under Physarum gyrosum, p. 111, Mon.

2. Physarum lateritium (Berk. & Rav.) Rost.

1873. Didymium lateritium Berk. & Rav., Grev., II., p. 65.

1875. Physarum ditmari lateritium Rost., Mon., App., p. 9.

1879. Physarum inequale Peck, Rep. N. Y. Mus., XXXI., p. 40.

1892. Physarum chrysotrichum Berk. & C., Massee, p. 300.

1894. Physarum inequale Peck, Lister, Mycetozoa, p. 60.

1896. Physarum lateritium (Berk. & Rav.) Morg., Jour. Cin. Soc., p. 95.

1899. Physarum lateritium (Berk. & Rav.) Morg., Macbr., N. A. S., p. 33.

1911. Physarum lateritium Morg., List., Mycetozoa, 2nd ed., p. 82.

Plasmodium scarlet. Sporangia gregarious, sessile, globose or sub-globose, or sometimes plasmodiocarpous, yellowish or orange, everywhere, when fresh, spotted with minute scarlet granules; the peridium thin, more or less rugulose; columella none; capillitium delicate, generally yellow, with nodules conspicuous, yellow or reddish; spores violet-brown in mass, by transmitted light pale violet, minutely roughened, 7–9 µ.

A well-marked species easily recognized by the characters cited. The extent of lime deposit at the capillitial nodes varies; sometimes very little. This accounts for Berkeley's generic reference. On the other hand, Lister makes the rounded lime knots "each knot with a red centre surrounded by yellow, round, lime-granules" diagnostic. This pied condition does not come out in any of our specimens. The capillitium in broken specimens soon fades, tends to white, etc.

New York, Pennsylvania, Ohio, Colorado, and south. Ceylon, Java, Brazil.

3. Physarum vernum Somm.

1829. Physarum vernum Somm., Fries, Syst. Mycol., III., p. 146.

1875. Physarum cinereum (Batsch), Rost., Mon., p. 102, in part.

1875. Badhamia verna Rost., Mon., p. 145.

1894. Badhamia panicea Rost., List., Mycetozoa, p. 34.

1899. Physarum cinereum (Batsch) Rost., Macbr., N. A. S., p. 34 (in part).

1911. Physarum vernum Somm., Lister, Mycetozoa, 2nd ed., p. 75.

"Plasmodium white." Sporangia sessile, generally plasmodiocarpous white, nearly smooth; peridium more or less testaceous not scaly, but breaking irregularly; capillitium densely calcareous, the nodules angular, branching, sometimes united to form a pseudo-columella; spores dusky violaceous, rough, 10–12 µ.

Sommerfeldt's description quoted by Fries, l. c., evidently concerned a less calcareous phase. Fries by his annotation relieves somewhat the reader's uncertainty.

Rostafinski calls this a badhamia but describes a physarum, and the form has, as is believed, been consistently confused with P. cinereum by every student of the group from the days of DeBary until now. In the second edition of the Mycetozoa, Lister clears the situation by transferring the species to Physarum, and calling attention to spore-dimensions. The fact is, the species in external appearance so much resembles P. cinereum, that the unaided eye cannot distinguish one from the other. Curiously enough, Rostafinski describes the form he had before him as "one of the rarest." Doubtless had he gone back to his specimens of P. cinereum he had found plenty, for in Europe it seems abundant everywhere. In this country it is P. cinereum as now defined, that is rarer, although not uncommon. From all connection with Badhamia, as representing B. panicea it should, as would appear, be withdrawn once for all.

4. Physarum sinuosum (Bull.) Weinm.

Plate VIII., Figs. 6 and 6a, and Plate XIX, Fig. 15.

1791. Reticularia sinuosa Bulliard, Champ., p. 94; t. 446, Fig. 3.

1796. Physarum bivalve Persoon, Obs. Myc., I., p. 6; t. III., Fig. 2.

1828. Physarum sinuosum Wein., Fries teste, l. c.

1828. Angioridium sinuosum Grev., Scot. Crypt. Fl., 310.

1829. Physarum sinuosum Fries, Syst. Myc., III., p. 145.

1875. Physarum sinuosum (Bull.) Rost., Monograph, p. 112.

1892. Physarum sinuosum Rost., Massee, Mon., p. 305.

1894. Physarum bivalve Pers., Lister, Mycetozoa, p. 57.

1896. Angioridium sinuosum (Grev.), Morg., Cin. Soc. Nat. Hist., p. 75.

1899. Physarum sinuosum (Bull.) Wein., Macbr., N. A. S., p. 28.

1911. Physarum sinuosum Wein., Lister, Mycetozoa, 2nd ed., p. 76.

Sporangia distinct or plasmodiocarpous, the plasmodiocarp creeping in long vein-like reticulations or curves, laterally compressed; sometimes distinct and crowded, always sessile. Peridium double; the outer thick, calcareous, fragile, snow-white; the inner delicate, the dehiscence by more or less regular longitudinal fissure. Capillitium strongly developed with abundant white, calcareous granules. Spores smooth, dull violet, 8–9 µ. Plasmodium pale gray, or nearly white.

Easily recognized at sight by its peculiar form, bilabiate and sinuous. Apart from microscopic structure, perfectly described by Fries, Syst. Myc., p. 145. Bulliard called it Reticularia sinuosa. Habitat various, but not infrequently the upper surface of the leaves of living plants, a few inches from the ground. The two sorts of fructification often occur side by side, or merge into one another from the same plasmodium. Where the substratum affords room the plasmodiocarpous style prevails; in narrower limits single sporangia stand. The calcareous deposit on the peridium is usually very rich and under a lens appears made up of countless snowy or creamy flakes. Forms occur, however, in which these outer calcic deposits are almost entirely wanting; the peridium becomes transparent, the capillitium visible from without. Judging from material before us, this appears to be the common presentation in western Europe. See also No. 5 following.

Widely distributed. New England to the Carolinas, and Louisiana west to South Dakota and Nebraska, Iowa and Washington.

5. Physarum bitectum List.

Plate XIX., Fig. 16.

1891. Physarum diderma Rost., List., Jour. Bot., XXIX., p. 260.

1894. Physarum diderma Rost., List., Mycetozoa, p. 57.

1911. Physarum bitectum List., Mycetozoa, 2nd ed., p. 78.

Sporangia gregarious, sub-globose, sessile or plasmodiocarpous, smooth white or pallid, terete or somewhat compressed; peridium double, the outer wall calcareous, free and deciduous above, recurved and persistent below; the inner, smooth, pale purplish, more persistent; dehiscence more or less irregular beginning at the top; capillitium of large white nodules connected by short hyaline threads; spores generally spinulose, violaceous brown, 9–10 µ.

As suggested by the author of this species it is properly a variety of P. sinuosum; certainly is, as it presents itself in this part of the world. Of the species last named we have compressed forms opening by narrow fissure along their knife-edged summit, with scarce place for capillitium at all between the approaching walls; again we have colonies of sporangia quite terete, calcareous without, opening in fragmental fashion at the top, displaying sometimes the thin membranous inner wall but at length fissured and gaping as in the more usual phase figured by authors, where the plasmodiocarp is simply compressed but not extravagantly thin. Both types occur in the western mountains, forms with and without calcium, fissured by wider or narrower cleft, from the same plasmodium; forms bilabiate and forms opening at first to display an inner peridium; forms globose with narrow base, but apex cleft, and forms ellipsoidal, yet compressed, opening like the gaping of some tiniest bivalve; did not Persoon say P. bivalve! all are bivalvular at the last! Nay; but what are these? Here are some of the shorter forms become suddenly obovate, and are actually mounted on stipes! Surely variation in the same plasmodium can no farther go![22]

Not rare. Colorado to the Pacific Coast. Evidently a western-American variation of Bulliard's European type. The latter occurs abundantly in Iowa on the shores of Lake Okoboji; otherwise not common.

6. Physarum bogoriense Racib.

1898. Physarum bogoriense Raciborski, Hedw., XXXVII., p. 52.

Sporangia sessile, elongate, creeping but not reticulate, semicircular in transverse section, sometimes globose or depressed globose; peridium double, the outer thick coriaceous, yellow or brown, dehiscing stellately into persistent more or less triangular reflected lobes, remote from the thin, colorless inner wall; columella none; capillitium feebly developed, the nodes white, large, isodiametric; spores bright violet, smooth, 7–8 µ.

This species is not uncommon in the mountains of Colorado where it has been taken at various stations by Bethel. It is reported from Pennsylvania and South Carolina. Raciborski describes it from Java.

In habit it is very much like some forms of P. sinuosum but differs in the depressed, rather than compressed sporangia, and in the brown color of the outer peridium.

7. Physarum alpinum G. List.

1910. Physarum alpinum G. Lister, Jour. Bot., XLVII, p. 73.

Sporangia globose and sessile or plasmodiocarpous, dull yellow, smooth or scaly; peridium double, the outer wall densely calcareous, separating irregularly from the membranous inner wall; capillitium densely calcareous, the nodes large, more or less branched, yellow; spores purple brown, closely and minutely warted, 9–14 µ.

This species is based by its author upon a gathering made in California by Dr. Harkness and named by Phillips who received it in England, badhamia inaurata. He seems not to have described it. Since its first appearance, the form has been found repeatedly in the Juras. Specimens are before me from Mt. Rainier believed to be the same. The plasmodiocarpous habit and yellow capillitium separate this from related P. contextum and P. mortoni.

Europe, California, Washington.

8. Physarum diderma Rost.

Plate XVIII., Fig. 9.

1875. Physarum diderma Rost., Mon., p. 110.

1898. Physarum didermoides var. lividum List., Jour. Bot., XXXVI., p. 162.

1899. Physarum diderma Rost., Macbr., N. A. S., p. 30.

1911. Physarum testaceum Sturgis, List., Mycetozoa, 2nd ed., p. 79.

Sporangia snow-white, clustered, sessile or narrowly adnate, globose or polygonal by mutual compression; peridium double, the outer dense, fragile, thick, calcareous, the inner delicate, remote, translucent, capillitium well developed, the calcareous nodules white, rounded or angular, sometimes uniting to form a pseudo-columella; spore-mass black; spores purplish, distinctly rough, 10–12 µ.

A beautiful and distinct species. As others in the group with which it is here associated, it is a physarum with the outward seeming of a diderma. It occurs in Europe, therefore it is safe to assume that Rostafinski saw it. So well marked it is that any good description will define it, and Rostafinski describes it perfectly, adequately.[23]

Mr. Lister having used for another species the name we here apply—see under P. bitectum—referred this present form to P. didermoides Rost., l. c. Professor Sturgis, convinced that such reference was at least doubtful, gave to our American gatherings the distinctive name above, citing specimens from Massachusetts, from Colorado, and from California. Curiously enough he also includes specimens of R. didermoides var. lividum List., sent from England!

Rare! Certainly rare in Europe and so far seldom seen in the United States, though widely distributed. Specimens are before us from Ohio, Michigan, Iowa, Oregon. No doubt the mountains of the north Pacific coast, a region to-day almost unsearched, will yet afford the species in abundance.

As stated Mr. Lister first applied the name P. diderma to a plasmodiocarpous form occurring in England and near P. sinuosum. More lately, Mon., 2nd ed., p. 78, he adopts a new specific name, P. bitectum for the English specimens, and enters P. diderma as a probable synonym for P. lividum R. Evidently our present form as described above has not come to Mr. Lister's view. He says the original type is not to be consulted.

There is really no more merit in this later comparison than in that discarded. The species P. diderma is not P. lividum, but stands as originally delimited, and will, doubtless, some day yet again appear in its own behalf upon the witness-stand of time; when, as before, a Frenchman in DeBary's old-time haunts may rise to give it welcome, brought back by some keen-eyed Polish student eager now in the arts of peace, from Warsaw's shady groves.

9. Physarum contextum Persoon.

Plate IX., Figs. 3 and 3a.

1796. Diderma contextum Persoon, Obs. Myc., I., p. 89.

1801. Physarum contextum Persoon, Syn. Meth., p. 168.

1829. Diderma contextum Persoon, Fries, Syst. Myc., III., p. 111.

1873. Diderma ochroleucum Berk. & C., Grev., II., p. 52.

1879. Diderma flavidum Pk., N. Y. Rep. State Mus., XXXI., p. 55.

Sporangia distinct, sessile, densely crowded, sub-rotund reniform more often elongate, interwoven; peridium double; the outer rather thick, calcareous, yellow, or yellowish white, the inner thin, yellowish; capillitium white, containing numerous large, irregular calcareous granules; columella none; spores deep violet, 11–13 µ, covered with minute spinules.

This singular species occurs not rarely upon the bark of fallen twigs, upon bits of straw or grass-stems lying undisturbed upon the ground. In such a position the slime-mould covers, as with a sheath, the entire substratum. The outer peridium, especially its upper part, is entirely evanescent, our Fig. 3 shows the sporangia with upper outer peridium wanting. Not rare in summer and autumn.

New England, New York, Pennsylvania, Ohio, Wisconsin, Illinois, Iowa, Colorado, Oregon, Nicaragua.

10. Physarum conglomeratum (Fr.) Rost.

1803. Spumaria granulata Schum., Enum. Pl. Saell., II., p. 196, No. 1419.

1803. Spumaria minuta Schum., l. c.

1829. Diderma granulatum Schum., Fries, S. M., III., p. 110.

1829. Diderma minutum Schum., Fries, l. c., p. 111.

1829. Diderma conglomeratum Fries, l. c., p. 111.

1875. Physarum conglomeratum (Fr.) Rost., Mon., p. 108.

1892. Physarum rostafinskii Massee, Mon., p. 301.

1894. Physarum conglomeratum Rost., Lister, Mycetozoa, p. 58.

1899. Physarum conglomeratum (Fr.) Rost., Macbr., N. A. S., p. 31.

1911. Physarum conglomeratum Rost., List., Mycetozoa, 2nd ed., p. 80.

Sporangia depressed, globose, or irregular, sessile, more or less aggregated, ochraceous-yellow, peridium double, the outer, thick, cartilaginous, at length irregularly ruptured, and reflexed, disclosing the more delicate, ashen-gray, inner membrane which encloses capillitium and spores; capillitium abundant, showing large, white irregular calcareous thickenings which are often consolidated in some sporangia tend to aggregate at the centre; spore-mass brown, spores violaceous, slightly roughened, 8–10 µ.

This beautiful species shows a peridium as distinctly double as in any diderma. The outer peridium is reflexed exactly as in some species of that genus; is yellow without, white within, and withal long persistent. The capillitium of course distinguishes the species instantly as a physarum. By the size of the spores it is distinguished from the species preceding. This being a decisive specific character the synonymy prior to Rostafinski is somewhat uncertain. The specific name adopted by the Polish author is therefore approved, although perhaps not the earliest.

Rare. The only specimens thus far are from Tennessee and Louisiana.

11. Physarum mortoni Macbr. n. s.

Plate XX., Figs. 2, 2 a.

Sporangia gregarious, clustered but distinct, sessile small, about .75 mm., bright yellow, peridium double. The outer rough, breaking up into comparatively few rather large deciduous scales, the inner peridium white, calcareous, both persisting below to form a distinct cup; capillitium lax, the nodes white, large, angular; columella none; hypothallus none; spores distinctly rough, dark brown with the usual purple shadow, 10–12 µ.

A very distinct little species related, no doubt, to P. contextum, but different in habit. It is never crowded, shows no plasmodiocarpous tendencies, while the outer peridium is generally deciduous except at the base and falls in flakes.

Collected several times in the Three Sisters Mountains of Oregon by Professor Morton E. Peck.

12. Physarum brunneolum (Phillips) Mass.

Plate XX., Figs. 7, 7 a.

1877. Diderma brunneolum Phillips, Grev., V., p. 114.

1888. Diderma brunneolum Phill., Saccardo, Syll. Fung., No. 1292.

1892. Physarum brunneolum Phill., Massee, Mon., p. 280, Figs. 221–222.

1894. Craterium pedunculatum Lister, Mycetozoa, p. 71.

1911. Physarum brunneolum Mass., Lister, Mycetozoa, 2nd ed., p. 63, Pl. 69, Fig. a.

Sporangia scattered or gregarious, but not crowded, sessile, globose or sub-depressed; peridium double, thick, smooth or polished, yellow brown, stellately dehiscent, the segments reflexed, white within; columella none; capillitium dense, with nodes numerous, large irregular, internodes thin and short; spores globose, lilac, minutely warted, 6–7 µ.

This form was first described in Grevillea, V., p. 114, as Diderma brunneolum Phillips. Later, students of the specimens preserved by Mr. Phillips, concur that we have to do not with a diderma, but with a craterium, Lister, or physarum, Massee. There seems no reason why we should not respect the decision of Massee, whose description is here quoted in form somewhat abridged. The peridium is about as double as in the many physarums, not more so; the inner membrane so delicate as only occasionally to be revealed except to scrutiny most searching. But the appearance as a whole is as of some brown diderma; only the calcareous capillitium abides to prevent mistaken reference.

When opened by irregular dehiscence from above, the persisting cup-like base of the sporangium recalls Leocarpus fragilis; but then again the capillitium is different.

California, Portugal; Colorado,—Sturgis.

13. Physarum cinereum (Batsch) Pers.

Plate IX., Figs. 4, 4 a, 4 b.

1786. Lycoperdon cinereum Batsch, Elench. Fung., p. 249, Fig. 169.

1801. Physarum griseum Link, Diss., I, p. 27.

1805. Physarum cinereum Persoon, Synopsis, p. 170.

1829. Didymium cinereum Batsch, Fries, Syst. Myc., III., p. 126.

1829. Physarum plumbeum Fries, Syst. Myc., III., p. 142.

1875. Physarum cinereum Batsch, Rost., Mon., p. 102, in part.

1896. Physarum plumbeum Fr., Morgan, Myx. Mi. Val., p. 98.

1899. Physarum plumbeum Fr., Macbr., N. A. S., p. 35.

1909. Physarum cinereum (Batsch) Pers., Torrend, Flore des Myx., p. 183.

Plasmodium watery white, or transparent, wide streaming on decaying sod, etc. Sporangia sessile, closely gregarious, or even heaped, sub-globose, elongate or plasmodiocarpous, more or less calcareous, gray; peridium simple, thin, more or less densely coated with lime; capillitium strongly developed, the nodes more or less richly calcareous, the lime-knots rounded, angular; spore-mass brown, spores clear violaceous-brown, 6–7 µ, distinctly warted.

This delicate, inconspicuous species is well defined by the characters given. It occurs not rarely on richly manured ground, in meadows, lawns, or even on the open prairie. The plasmodium may form rings several inches in diameter, scattered here and there over a surface several square feet in extent, in fruit ascending the blades of grass, completely covering these with the crowded sporangia. The color of the fruit is well described in the specific name; gray or ashen gray. The spores are very distinctly papillate; in some specimens, however, almost smooth; in few instances, rough.

Common. New England west to the Black Hills and Pacific coast. Cosmopolitan.

The present species well illustrates the difficulty confronting the author of to-day who, discussing a group of microscopic organisms, would fain use the nomenclature of his predecessors, honored, but equipped with insufficient lenses. Here is a species reported common in Europe, observed by every mycologist there, from Micheli down, and yet awaiting adequate description until Rostafinski in his great book, gives the results of microscopic analysis. We are now really dealing with P. cinereum Rost; P. cinereum Batsch is a compliment to certain rather clever water-color drawings.

Rostafinski gives a long list of synonyms, none, it is believed, represent American forms; and without taking careful thought, surely no one would rudely disturb such honorable interment; but, in his description the range of spore-measurement, 7–13.3 µ, gives us pause, and raises the suspicion that possibly, in one case or another, the sepulture were perhaps premature. The range is too great! Perhaps, in the series offered in confirmation, small-spored forms represent one species, large-spored, something else?

European students may decide this at their leisure. But Rostafinski having, not without much labor, practically completed his review of the physaroid forms had almost finished the last genus Badhamia, when his mind perhaps returned, no doubt with some lingering misgivings, to the thirteenth species in his physarum list. There were there, he recalled, some large-spored specimens which had rather badhamioid capillitium. The sessile physarums of Fries were also before him, those especially, "floccis albis." Of these one shall be B. panicea, one B. lilacina and one B. verna, described as having rather delicate colorless capillitial tubes combined in a loose net, the calcareous deposits about the enlarged intersections scanty, the spores 12.5 µ.

The description of the fructification as a whole is a condensed statement of that which describes P. vernum, and all taken together indicates some physarum. See now No. 3 preceding, p. 51.

P. plumbeum Fr. belongs here. It has similar spores, the only difference is a less calcareous peridium and more scattered habit of fructification with more nearly regular, depressed-globose sporangia.

P. cinereum Pers. as cited by Link, op. cit., is apparently a badhamia, may be P. vernum, while P. griseum is probably the present species.

14. Physarum virescens Ditmar.

Plate VIII., Figs. 7, 7 a, 7 b.

1817. Physarum virescens Ditmar, Sturm, Deutsch. Fl. Pilze, I., p. 123, Pl. 61.

1875. Physarum ditmari Rost., Mon., App., p. 8.

1892. Physarum ditmari Rost., Macbr., Bull. Lab. Nat. Hist. 1a., II., p. 155.

1894. Physarum virescens Ditmar, Lister, Mycetozoa, p. 65.

1909. Physarum virescens Ditmar, Torrend, Flo. d Myx., No. 207.

1911. Physarum virescens Ditmar, Lister, Mycetozoa, 2nd ed., p. 83.

Sporangia sessile, crowded or heaped in small bunches, a dozen or more sporangia in one pile, spherical, ovoid or elongate, yellow or greenish yellow; peridium thin, fragile; capillitium delicate, with rather small, irregular, yellowish, calcareous nodes; columella none; spores bright violet, minutely roughened, 7–9 µ.

This species occurs more commonly on moss-tufts, with which it is frequently con-colorless, or escaped on dead leaves, etc. The peridium is flecked with calcareous scales or grains stained yellow or green, and to these the whole fruit owes its peculiar color. The color and aggregate, heaped sporangia are distinctive macroscopic characters.

In the Monograph, p. 113, Rostafinski adopted properly Ditmar's name for this species. Upon later consideration, in the Appendix, p. 8, he changed the name, writing P. ditmari, on the ground that virescens was descriptive of a character to which the species in question occasionally refuses to conform. Most authors since Rostafinski have simply accepted his suggestion, so that the species is often entered P. ditmari Rost. P. virescens is certainly to be preferred. N. A. F., 2692.

Canada, New England, New York, Pennsylvania, Ohio, Iowa, Black Hills, South Dakota.

15. Physarum rubiginosum Fries.

1817. Physarum rubiginosum Fries, Symb. Gast., p. 21.

Plasmodium scarlet. Sporangia globose or cylindric, sessile or sometimes narrowed to a stem-like base as if short-stipitate, olivaceous brown with sometimes a flush of red; the peridium simple, thin rugulose or plain, the calcareous scales few, or apparently included; columella none; capillitium dense, the nodules rather large, angular, rusty brown; spores dull violaceous, gently roughened, about 10 µ.

A beautiful well-marked species, but evidently rare in North America. Our only typical specimens are from the gatherings by Mr. Wingate, part of which is by Lister referred to this species, Mycetozoa, 2nd ed., p. 82.

P. rubiginosum Fr. in the N. A. S., 1899, is based on certain west coast specimens now known as Badhamia decipiens Berk.

In Colorado there occurs a plasmodiocarpous form of the species. It has the characteristic spore and capillitium but in form and habit differs very decidedly. The fructification is a delicate netted plasmodiocarp, the tubule about .5 mm., bright red; the peridium simple, cartilaginous, dehiscent from above, and flecked with just here and there a red calcareous scale.

Collected at Palmer Lake; Professor Bethel.

16. Physarum instratum Macbr. n. s.

1899. Physarum thejoteum Macbride, N. A. S., p. 36, not Fries, as cited.

1911. Physarum virescens Ditmar, Lister, Mycetozoa, 2nd ed., p. 83.

Sporangia very small, closely crowded on a delicate, more or less visible hypothallus, often connate, but not superimposed, sub-spherical, dull orange, brownish or tawny; peridium thin, violaceous, covered with very minute yellow calcareous scales; columella none; capillitium lax, sometimes almost wanting; the nodules small, yellowish or brownish, occasionally confluent; spore-mass violaceous, spores by transmitted light, violet-tinted, smooth or nearly so, 6–7 µ.

Not uncommon in the Mississippi valley, where it sometimes is passed by the collector as an immature form of some other species. The appearance is very characteristic, unlike P. virescens in both habit, size, and color. Colonies are quite often three inches in length. The most common habitat seems to be rotten oak, especially fragments of charred logs, etc.

Ohio, Illinois, Missouri, Iowa, Nebraska.

This species presents a decidedly well-marked form, so much so that it may be easily recognized at sight, without a lens. It therefore requires special discussion, and although in the spore-characters and some minor but not determinative details it agrees with P. virescens Ditm. to which it is by European authors sometimes referred, it seems nevertheless deserving of specific recognition, since in its entire habit and expression it is not only completely different but is constant in its specific peculiarities, much more so than is the suggested related form.

In the first edition of this work, the form was referred to Physarum thejoteum of Fries. This was the judgment of our American colleague, Professor A. P. Morgan whose work in this group is widely recognized. Fries admits, Syst. Myc., III., p. 142, that while he deems P. thejoteum very distinct, he yet has not seen P. virescens Ditm.! Since our form apparently does not occur in Europe, specimens which the distinguished author had before him were doubtless representatives of the now commonly recognized species of Ditmar.

For these reasons it seems appropriate to give the American type a suitably descriptive title.

17. Physarum megalosporum MacBr.

Plate XVI., Figs. 7 and 7 a.

1917. Physarum melanospermum Sturgis, Mycologia, Vol. IX., p. 323.

Sporangia gregarious, sessile, or short stipitate depressed, annulate, or at least umbilicate above, white or anon roseate, about .75 mm; stipe, when present, short, thick, black or dark brown! hypothallus none; columella none; capillitium strongly calcareous, an abundance of irregular white nodules burden the delicate net; spores dark sooty brown with a shade of purple by transmitted light, verruculose, 12–13 µ.

This species is recognizable at once by its regular, uniform, depressed, annulate or pitted sporangia, scattered evenly over the habitat of rotten leaves or wood. It suggests a didymium in its form and habit, but is near a badhamia. Colorado; Bethel, 1908.

18. Physarum confertum Macbr. nom. nov.

Plate XV., Figs. 1, 1 a, 1 b.

1899. Physarum atrum Schw., Macbr., N. A. S., p. 36.

1911. Physarum atrum Schw., Lister, Mycetozoa, 2nd ed., p. 74.

Sporangia small about .2–.3 mm. in diameter, gregarious, confluent, clustered or heaped, dull violaceous brown; peridium thin, more or less transparent, generally limeless but sometimes lightly sprinkled with minute white flecks: capillitium scanty, the calcareous nodes small, rounded, elongate, white! columella none; spores violet-brown, distinctly warted, 10–12 µ.

Having been assured on information believed trustworthy that the Schweinitzian herbarium confirmed the identity of the species before us, in the first edition of this work the form was listed as P. atrum Schw. Meantime in the herbarium referred to, at Philadelphia the original type of P. atrum still exists. My valued correspondent, Mr. Hugo Bilgram, has recently given it careful study. It is a limeless P. didermoides (Pers.) R.! Small wonder we have had trouble! Exit Physarum atrum Schw.

The species is not uncommon, especially eastward; has been generally ignored for reasons cited.

Distinguished from everything else by the color and small size of the heaped sporangia. It resembles some phase of P. virescens where the sporangia are small and somewhat heaped or rather aggregated, and scantily supplied with lime; but in such case the lime is yellow and the spores are small.

This species has also been constantly referred to our confused P. cinereum, P. plumbeum, etc., but Schweinitz, who certainly had seen P. cinereum in Europe, since he cites it, under several forms, in the Conspectus, found the species in America and proceeded in Pennsylvania in December to find something else, very different as he thought, and in fact. He called this new discovery P. atrum, "beautifully reticulate", he says "like P. cinereum but larger."

Most American students in an effort to keep faith with their pioneer mycologist, have taken cue from the specific name, looking for something black, heedless that in Pennsylvania almost any delicate thing has 'dark looks' in the middle of the winter! Berlese in Saccardo Syll. VII., p. 350, regarding P. atrum as a synonym, writes for the black American specimens, P. reticulatum, emphasizing another Schweinitzian descriptive adjective. But P. atrum Schw. has had place in literature to this hour.

19. Physarum melleum (Berk. & Br.) Mass.

1873. Dydymium melleum Berk. & Br., Jour. Linn. Soc., XIV., p. 83.

1873. Didymium chrysopeplum Berk. & C., Grev., II., p. 53.

1876. Physarum schumacheri Spr. var. melleum Rost., Mon., App., p. 7.

1892. Physarum melleum Massee, Mon., p. 278.

1896. Cytidium melleum (Berk. & Br.), Morg., Jour. Cin. Soc., p. 83.

1899. Physarum melleum (Berk. & Br.), Mass., Macbr., N. A. S., p. 47.

1911. Physarum melleum Mass., Lister, Mycetozoa, 2nd ed., p. 46.

Sporangia scattered, stipitate, globose, flattened below, clear yellow or honey colored; stipe short, about equaling the sporangium, pure white, somewhat wrinkled; columella small but distinct, white; hypothallus none, capillitium abundant, open, snow-white, with rather large angularly stellate nodes; spore-mass brown, almost black; spores by transmitted light, pale violet or lilac-tinted, almost smooth, 7.5–10 µ.

Easily distinguished by its white stipe, columella and capillitium in contrast with yellow peridial walls. N. A. F., 1395. Massee refers this number erroneously to P. schumacheri Rost. The description and specimen do not correspond. By that name the species has however, been hitherto known in the United States.

Eastern United States, common; rare west of the Mississippi.

Reported from Brazil, Japan and the tropic islands round the world. Portugal.

20. Physarum citrinum Schumacher.

1803. Physarum citrinum Schum., Enum. Pl. Saell., II., p. 201.

1911. Physarum citrinum Schum., List., Mycetozoa, 2nd ed., p. 51.

Sporangia gregarious, scattered, globose, somewhat flattened below, pale yellow, citrine, stipitate; the peridium thin, covered almost completely with small calcareous scales; stipe stout, erect, fragile, tapering upwards, furrowed, opaque, arising from a small hypothallus which is anon continuous from one sporangium to the next; columella small, conical, yellow; capillitium a rather dense, delicate network, the calcareous nodules yellow, numerous, roundish, and generally small; spore-mass black; spores under the lens violaceous, almost smooth, about 8 µ.

This species seems to be rare in the United States. It resembles somewhat P. melleum, from which it is distinguished by its yellow stipe. P. galbeum is a smaller form, and lacks the columella. Rostafinski strangely confused the synonymy here, including even P. rufipes Alb. & Schw.

New England, Ohio, Colorado.

21. Physarum globuliferum (Bull.) Pers.

1791. Sphaerocarpus globuliferus Bull., Champ., Pl. 484, Fig. 3.

1801. Physarum globuliferum Pers., Syn., p. 175, T. III., Figs. 10, 11, 12.

1829. Diderma globuliferum Fries, Syst. Myc., III., p. 100.

1876. Physarum petersii farlowii Rost., Mon., App., p. 6.

1879. Physarum albicans Peck, Rep. N. Y. Mus., XXX., p. 50.

1893. Physarum columbinum Macbr., Bull. Lab. Nat. Hist. Iowa, II., 384.

1899. Physarum globuliferum (Bull.) Pers., Macbr., N. A. S., p. 45.

1911. Physarum globuliferum Pers., Lister, Mycetozoa, 2nd ed., p. 48.

Sporangia gregarious, stipitate, globose, or slightly depressed above, pale blue-gray or pure white; stipe sometimes equal to the sporangium, generally longer, slender, slightly wrinkled, white, or yellow, pallid, when longer tapering upward; columella white, conical, sometimes obsolete; hypothallus none; capillitium dense, but delicate, persistent, a close network of hyaline threads, with white or yellowish nodes sparingly thickened and calcareous, many without lime; spore-mass brown; spores by transmitted light, violet, minutely warted, 7.5–9 µ. Plasmodium greenish-yellow.

This species, very common eastward, rare west of the Mississippi, is at once very beautiful and very variable. Its several phases have been again and again observed and described too often by distinct specific or varietal names. A form from New York, with long, white stems and almost pure white sporangia, is P. albicans Peck. Forms occur like P. albicans, but flushed with rose throughout. From New England, specimens sent Rostafinski were by him deemed a variety of P. petersii Berk. & C., and called P. petersii var. farlowii Rost. By this name the species has been generally distributed in this country. N. A. F., 1120. Most gatherings of this species have small, somewhat ochraceous, sporangia, and pale yellow, or somewhat rusty, stipes. These latter, with somewhat heavier stem, represent Physarum simile Rost. A form collected sparingly in Iowa has short, white stipes and blue gray sporangia one-third larger than observed in the eastern types. This was recorded, l. c., as P. columbinum Macbr.; name already in use. The spores in the Iowa specimens are also a little larger, 8–10 µ. Pale cyanic and roseate forms also sometimes occur in late fruitings; see next species.

In all phases the persistent tenacity of the capillitium is a striking characteristic well noticed by Fries (l. c., p. 101): "Peridia a gleba omnimo libera, dein tota diffracta, evanescentia, ... capillitio compacto forma servata persistente." The peridium, except a small part below, all falls away, leaving the capillitium apparently intact, crowded with spores.

From England to Iowa; Canada, south to Louisiana and Mexico; apparently, in one form or another, cosmopolitan.

22. Physarum lilacinum Sturgis & Bilgram.

1917. Physarum lilacinum Sturg. & Bilg., Mycologia, Vol. IX., p. 323.

Sporangia gregarious, stalked, globose, erect, pale-lilac to pale Indian-red in color, 0.5 mm. in diameter; sporangium-wall membranous, beset with rounded masses of lilac or reddish lime. Stipe erect, broad-based, tapering upwards, calcareous, furrowed, paler than the sporangium or concolorous, 0.7–0.9 mm. long, about 0.1 mm. thick, columella conical or columnar, capillitium delicate, rigid, persistent; lime-knots small, rounded, composed of large, pale lilac, or reddish, spherical granules. Spores pale-brown, almost smooth, 8–9 µ.

Vicinity of Philadelphia,—Bilgram.

23. Physarum murinum Lister.

1894. Physarum murinum Lister, Mycetozoa, p. 41.

1899. Physarum ravenelii (Berk. & C.) Macbr., N. A. S., p. 48.

1911. Physarum murinum Lister, Mycetozoa, 2nd ed., p. 50.

Sporangia scattered, globose or perfectly spherical, ashy-brown, rugulose, stipitate; stipe elongate, pale brown, erect, generally tapering upward, calcareous, brittle; hypothallus none; columella short, hemispherical or bluntly conical; capillitium dense, much as in P. globuliferum, the calcareous nodules, umber, brownish or orange-yellow, small; spore-mass brown; spores by transmitted light, bright lilac, almost smooth, 7–9 µ.

A very distinct species, easily known by its peculiar drab-colored peridium and dull brown stalks. The author of the species allows for the capillitial nodes none other tint but brown. Under direct illumination many gatherings, especially where the sporangia are well blown out, show nodules of a bright orange tint.

Not rare in the eastern United States, to Missouri and Iowa. Reported also from western Europe.

Mr. Lister finds Didymium ravenelii Berk. & C., on which P. ravenelii (Berk. & C.) Macbr. is founded, referable to P. pulcherripes Pk.

24. Physarum pulcherrimum Berk. & Rav.

1873. Physarum pulcherrimum Berk. & Rav., Grev., II., p. 65.

1875. Physarum pulcherrimum (Berk. & Rav.) Rost., Mon., p. 105.

1879. Physarum atrorubrum Peck, Rep. N. Y. Mus., XXXI., p. 40.

1899. Physarum pulcherrimum Berk. & Rav., Macbr., N. A. S., p. 49.

1911. Physarum pulcherrimum Berk. & Rav., Lister, Mycetozoa, 2nd ed., p. 50.

Plasmodium dark red. Sporangia scattered or gregarious, globose, even, or somewhat wrinkled, dark red, stipitate; stipe cylindric, even, sub-concolorous or blackish; columella small or none; capillitium free from spores, whitish, with a slight pinkish tinge; spores dark brown in mass, dark red when separated, globose, smooth, 7.5–8.5 µ.

The capillitium is very delicate, and when cleared of spores the knot-like thickenings are seen to be very small and of a dark red color, to which is probably due the pinkish tinge which marks the whole. A part only of the thickenings are filled with lime granules. The dark red granules of the sporangium walls are abundant and appear to form a continuous crust.

This is P. atrorubrum Peck, and his description, l. c., has been closely followed. The very brief description in Grevillea, however, antedates the New York publication and, all inadequate as it is, no doubt applies to the same thing.

Not rare. New York, Pennsylvania, Ohio, Missouri, Iowa.

25. Physarum pulcherripes Peck.

1805. Physarum aurantiacum var. rufipes Alb. & Schw., Consp. Fung., p. 94.

1829. Diderma rufipes (Alb. & Schw.) Fries, Syst. Myc., III., p. 101.

1873. Physarum pulcherripes Peck., Bull. Buff. Soc. Nat. Hist., I., p. 64.

1873. Didymium erythrinum Berk., Grev., II., p. 52.

1873. Didymium ravenelii Berk. & C., Grev., II., p. 53.

1873. Physarum petersii Berk. & C., Grev., II., p. 66.

1875. Physarum schumacheri Spr. var. rufipes Alb. & Schw., Rost., Mon., p. 99.

1894. Physarum pulcherripes (Peck), Lister, Mycetozoa, p. 41.

1896. Cytidium rufipes (Alb. & Schw.) Morg., Jour. Cin. Soc. Nat. Hist., p. 81.

1899. Physarum rufipes (Alb. & Schw.) Morg., Macbr., N. A. S., p. 50.

1911. Physarum pulcherripes Peck., List., Mycetozoa, 2nd ed., p. 49.

Sporangia gregarious, dark-colored, sprinkled with orange flakes of lime, globose, the wall thin, deciduous, stipitate; stipe slender, erect, deep red, sometimes black below, pale or orange above, and supported on a well-developed hypothallus; columella scant or none; capillitium dense, the meshes and nodes unusually small and delicate, the latter reddish or yellow; spore-mass black; spores by transmitted light, violet-tinted, 8–10 µ., almost smooth.

The striking contrast of color between sporangia and stipes renders this species at sight, quite distinct from any related form. The peridia in the specimens before us are black or iridescent-black sprinkled more or less profusely with orange lime granules which sometimes cover all but the base. The stipe, springing from a small hypothallus, is dark red below for about one-fourth its height, then vermillion, above expanding slightly beneath the peridium; the columella scant or none. The capillitium is an elegant delicate net, with numerous small, uniformly regular, calcareous nodes, orange; by transmitted light, yellow. The spores, brown in mass, are, by transmitted light, pale violet, slightly papillose, 8–10, mostly about 8 µ. The plasmodium is probably yellow.