Subclass II. CELLULAR ACROGENS, or BRYOPHYTES.

Plants composed of cellular tissue only. Antheridia or archegonia, or both, formed upon the stem or branches of the plant itself, which is developed from the germinating spore usually with the intervention of a filiform or conferva-like prothallus.—Divided into the Musci, or Mosses, and the Hepaticæ.

Division I. HEPÁTICÆ.[1] (Liverworts.)

[Footnote 1: Elaborated for this edition by Prof. L. M. Underwood, of Syracuse, N. Y.]

Plants usually procumbent, consisting of a simple thallus, a thalloid stem, or a leafy axis; leaves when present 2-ranked, with uniform leaf-cells and no midvein; thalloid forms with or without a midvein, smooth or scurfy or scaly beneath and usually with numerous rootlets. Sexual reproduction by antheridia and archegonia, which are immersed in the thallus, or sessile or pedicelled upon it, or borne on a peduncled receptacle. The fertilized archegonium develops into a capsule (sporogonium) closely invested by a calyptra, which ruptures above as the ripened capsule (containing numerous spores and usually elaters) pushes upward. It is also commonly surrounded by a usually double involucre, the inner (often called perianth) more or less tubular, the outer tubular or more often foliaceous, sometimes wholly wanting. Propagation is also effected by offshoots (innovations), runners (flagella), or by gemmæ, which appear at the margin of the leaves or on the surface of the thallus, often in special receptacles.

Order 137. JUNGERMANNIÀCEÆ. Scale-Mosses.

Plant-body a leafy axis or rarely thallose. Capsule borne on a slender often elongated pedicel, splitting at maturity into 4 valves. Elaters mixed with the spores, mostly bispiral (unispiral in n. 1–3, 32, and 33, 1–3-spiral in n. 5 and 28). Antheridia and archegonia diœcious or monœcious, in the latter case either mingled in the same inflorescence, or separated upon the same branch, with the antheridia naked in the axils of the lower leaves, or on separate parts of the same plant. Leaves 2-ranked, incubous (i.e. the apex of each leaf lying on the base of the next above), or succubous (i.e. the apex of each leaf lying under the base of the next above), or sometimes transverse, with frequently a third row of rudimentary leaves beneath the stem.

Artificial Key to the Genera.

§ 1. Plant-body a leafy axis.

[*] Leaves complicate-bilobed (i.e. folded together) or with a small basal lobe.

[+] Lower lobe smaller than the upper.

[++] Root-hairs borne on the stems or underleaves.

1. Frullania. Lower lobe mostly saccate, more or less remote from the stem. Branches intra-axillary, the leaves on either side free.

2. Jubula. Lower lobe saccate; branches lateral, a basal leaf borne partly on the stem, partly on the branch.

3. Lejeunea. Lower lobe incurved, more or less inflated.

5. Porella. Lower lobe ligulate. Perianth triangular, the third or odd angle ventral.

[++][++] Root-hairs rising from the lower lobes.

4. Radula. Perianth compressed. Underleaves none.

[+][+] Upper lobe smaller than the lower, or the two somewhat equal.

[++] Leaves succubous as to their lower lobes.

15. Scapania. Involucral leaves 2; perianth dorsally compressed, the mouth truncate, bilabiate, decurved.

16. Diplophyllum. Involucral leaves few; perianth erect, round, the mouth denticulate.

[++][++] Leaves transverse.

25. Marsupella. Perianth tubular or somewhat compressed. (Compare also Jungermannia § Sphenolobus.)

[*][*] Leaves palmately 3–4- (or many-) cleft.

[+] Divisions numerous, capillary. Plants large, usually in conspicuous mats.

6. Ptilidium. Leaves palmatifid with ciliate margins.

7. Trichocolea. Leaves setaceously multifid.

[+][+] Leaves 3–4-cleft or parted; plants small, mostly inconspicuous.

10. Lepidozia. Leaf-divisions two cells wide or more.

11. Blepharostoma. Leaf-divisions only one cell wide.

[*][*][*] Leaves entire, emarginate, or 2–3-toothed or -lobed.

[+] Leaves closely imbricate on short julaceous stems.

27. Gymnomitrium. Involucre double, the inner shorter.

[+][+] Leaves deeply bilobed.

8. Herberta. Underleaves large. Perianth fusiform on an elongated branch.

12. Cephalozia. Underleaves mostly wanting; perianth mostly triangular on a short branch.

[+][+][+] Leaves incubous, mostly plane or depressed.

9. Bazzania. Leaves mostly 2–3-toothed. Perianth fusiform on a short branch.

14. Kantia. Leaves mostly entire. Perianth fleshy, pendulous, subterranean.

[+][+][+][+] Leaves succubous or transverse.

[++] Underleaves entire or nearly so.

13. Odontoschisma. Involucral leaves numerous, small, incised, those of the stem rounded or retuse.

21. Mylia. Involucral leaves 2, connate at base. Large.

22. Harpanthus. Involucral leaves few, smaller than the semi-vertical emarginate stem-leaves. Small.

24. Jungermannia. Involucral leaves few, mostly larger than the entire or bidentate stem-leaves. Medium-sized or large.

[++][++] Underleaves 2–4-cleft, -parted, or -divided.

17. Geocalyx. Involucre fleshy, saccate, pendent. Leaves bidentate; underleaves 2-cleft.

18. Lophocolea. Fruit terminal on the main stem or a primary branch. Involucral leaves distinct.

19. Chiloscyphus. Fruit on a short lateral branch. Involucral leaves distinct. (See also Jungermannia.)

[++][++][++] Underleaves mostly wanting.

a. Leaves entire or barely retuse.

23. Liochlæna. Involucral leaves distinct, like those of the stem; perianth truncate-depressed at the apex.

26. Nardia. Involucral leaves connate at base and adnate to the perianth.

b. Leaves bidentate or bilobed, rarely 3-lobed.

12. Cephalozia. Branches all from beneath. Perianth on a short branch, mostly trigonal with the odd angle beneath.

24. Jungermannia. Simple or branching laterally. Perianth terminal, mostly laterally compressed.

c. Leaves mostly spinulose or dentate.

20. Plagiochila. Involucral leaves large; perianth laterally compressed.

§ 2. Plant-body pseudo-foliaceous with succubous leaf-like lobes.

28. Fossombronia. Perianth large, campanulate.

§ 3. Plant-body a thallus.

[*] Thallus with a distinct costa.

29. Pallavicinia. Thallus 3–6´´ wide, mostly simple, the margins sinuate or undulate. Perianth tubular, at length dorsal.

30. Blasia. Thallus 3–6´´ wide, lobed, dichotomous, or radiate, the margins pinnatifid-sinuate.

32. Metzgeria. Thallus narrow (1–2´´), ciliate at the margins or on one or both sides.

[*][*] Thallus with an inconspicuous costa or none.

33. Aneura. Thallus rather narrow, mostly palmately or pinnately lobed. Sporogonium rising from the under side near the margin.

31. Pellia. Thallus wider, mostly simple or forked. Sporogonium rising from the upper surface.

1. FRULLÀNIA, Raddi. (Pl. 24.)

Leaves incubous, complicate-bilobed, the lower lobe usually inflated, helmet- or club-shaped; underleaves bifid, rarely entire, with basal rootlets. Diœcious or monœcious. Fruit terminal on the branches. Involucral leaves 2 or 4, larger than the stem-leaves; perianth 3–4-angled, mucronate. Calyptra pyriform, fleshy. Capsule globose, the lower third solid. Elaters truncate at each end, unispiral, adherent to the valves. Spores large, reddish, minutely muricate. Antheridia most often on a short branch, globose-oblong or cylindric. Archegonia 2–4, long-styled. (Named for Leonardo Frullani, an Italian Minister of State.)

§ 1. TRACHYCÓLEA. Perianth triangular in section, rough with tubercles or scales, or villous; lower leaf-lobe helmet-shaped, truncate at base.

[*] Lower leaf-lobe about three fourths the size of the upper.

1. F. Oakesiàna, Aust. Stems widely branching; fertile branches short; leaves obliquely orbicular, loosely imbricate, the lower lobe rotund, contiguous to the stem; underleaves ovate-rotund or subobovate, little wider than the stem, bifid; involucral leaves more or less connate, equally bilobed, the lobes entire, obtuse; perianth small, subobovate-pyriform, smooth or 1–7-nerved or alate both sides.—White Mts., on stunted spruce and birch trees.

[*][*] Lower leaf-lobe much smaller than the upper.

[+] Underleaves scarcely wider than the stem, ovate, bifid, the divisions entire, acute; perianth 1-carinate or smooth, except in n. 2; stems creeping.

2. F. Virgínica, Lehm. Stems short, irregularly branching; leaves crowded, ovate, entire, somewhat concave, the lower lobes sometimes expanded into a lanceolate lamina; underleaves round-ovate, bifid, twice the width of the stem; perianth compressed-pyriform, tuberculate, 2–4-carinate dorsally, 4-carinate ventrally.—On bark of trees, rarely on rocks; common.

3. F. Eboracénsis, Lehm. Branches clustered; leaves loose, imbricate on the branches, round-ovate, entire; perianth pyriform, slightly compressed and repand, smooth, obscurely carinate beneath and gibbous toward the apex. (F. saxatilis, Lindenb.)—On trees and rocks; common northward.

4. F. Pennsylvánica, Steph. Stems dichotomous; leaves imbricate, flat, ovate, mucronate or rarely obtuse, entire; lower lobe marginal, large, round-cucullate; underleaves broadly ovate, deeply parted, the divisions long-acuminate; diœcious; antheridial spikes on short lateral branches, elongated; lobes of the involucral leaves acuminate, much narrowed at base, and the large underleaves carinate-concave, deeply parted, their apiculate divisions entire or toothed.—Shaded rocks, Stony Creek, Carbon Co., Penn. (Rau). Known only from the original description.

5. F. saxícola, Aust. Stems numerous, widely branching; leaves orbicular, scarcely oblique, flat; lower lobe near the stem, small, or rarely larger and round-galeate; underleaves scarcely wider than the stem, subovate, bifid; perianth broadly oblong, bowl-shaped with very short mouth, papillose, abruptly broad-carinate beneath, 1–many-nerved each side of the keel, 2-angled.—Sloping dry trap rocks, Closter, N. J. (Austin).

[+][+] Underleaves 2–3 times wider than the stem, round or subquadrate, bifid, the divisions blunt or truncate.

[++] Leaves lax, rather distant; lower lobe mostly expanded, ovate-lanceolate.

6. F. æolòtis, Nees. Procumbent, irregularly branched or subpinnate; leaves semi-vertical, subsquarrose, obliquely cordate, the lower lobe expanded; underleaves ovate, acutely bifid, the upper margin angular-dentate or entire; sporogonium unknown.—On trees and rocks, chiefly in mountain regions.

[++][++] Leaves close-imbricate; lower lobe galeate, seldom expanded except on terminal leaves.

7. F. squarròsa, Nees. Decumbent, pinnately branching, the short fertile branch lateral; leaves subvertical, suborbicular, obtuse, entire; lower lobe obovate-cucullate or galeate, subappressed; underleaves cordate or rounded, sinuate-subdentate, slightly bifid; perianth oblong, triquetrous, convex dorsally, strongly keeled ventrally.—On rocks and trees, N. Y. to Ohio, and southward; rather common.

8. F. plàna, Sulliv. Procumbent, widely branching or subpinnate; leaves orbicular, subimbricate; lower lobe very small, as broad as long, close to the stem; underleaves rather large, flat, rounded, slightly bifid; monœcious; perianth oblong-oval or subobovate, triquetrous, dorsally sulcate, acutely keeled ventrally; antheridial spikes globose.—Shaded rocks, N. Y. and N. J. to E. Tenn.

9. F. dilatàta, Nees. Loosely and widely pinnate; leaves round, entire, opaque; lower lobe subrounded, cucullate, close to the stem; underleaves subquadrate, toothed at the anterior angles; involucral leaves with 2 or 3 entire lobes; perianth tuberculate, retuse.—Rocks and trunks of trees; rather common. (Eu.)

§ 2. THYOPSIÉLLA. Perianth smooth; leaves semicordate at base (marked by a central moniliform row of cells, or sometimes in n. 12 by a few scattered large cells); lower lobe near the stem (except in n. 11), cylindric-saccate, mostly erect; underleaves round-oval, the margin entire, recurved; diœcious.

[*] Leaves orbicular.

10. F. Asagrayàna, Mont. (Pl. 24.) Creeping, simply pinnate; leaves concave, obtuse, decurved; lower lobe oblong-clavate, emarginate at base; underleaves oblong, flat, 2-cleft, the sinus obtuse; involucral leaves unequally 2-cleft, the dorsal segment oblong, pointed, nearly entire, the ventral subulate; perianth pyriform, 3-sided, obtusely keeled beneath. (F. Grayana of authors.)—Rocks and bark of coniferous trees; frequent.

11. F. Tamarísci, Nees. Bipinnately branching, somewhat rigid; leaves obtuse, mucronately acute or subacuminate, decurved, entire; lower lobe distant from the stem, oval or oblong; underleaves quadrate-ovate or obovate, emarginate, the margin revolute; involucral leaves bifid, serrulate; perianth oblong, sulcate dorsally, obtusely keeled ventrally.—N. Eng. and southward; rare. (Eu.)

[*][*] Leaves oblong from a narrowed base.

12. F. fragilifòlia, Tayl. Procumbent, subpinnate, the alternate flattened branches subremote; leaves subimbricate, ascending, recurved, entire; lower lobe oblong-galeate; underleaves round-obovate, flat, appressed, bifid, the margins entire or angled; perianth obovate-cordate, concave dorsally, keeled ventrally; involucral leaves subequally lobed, obtusely few-toothed. (F. polysticta, Mont. F. Sullivantiæ, Aust.)—On trees in a cedar swamp, Urbana, Ohio (Sullivant). (Eu.)

2. JÙBULA, Dumort. (Pl. 25.)

Characters nearly as in Frullania. Leaves large and flat, an axillary one at the base of each branch without a lower lobe. Calyptra turnip-shaped, abruptly globose above. Monœcious, with 2 antheridia in each leaf of a spike-like branch, and the archegonia mostly solitary. (Name from juba, a mane, alluding to the persistent elaters.)

1. J. Hutchínsiæ, Dumort., var. Sullivántii, Spruce. Subdichotomously branching; leaves dark olive-green, subimbricate, obliquely ovate, acute, entire or subrepand; lower lobe saccate, rather remote from the stem, not spurred as in the European form; underleaves roundish, serrate or entire; involucral leaves bifid, serrate; perianth triangular-obpyriform. (Frullania Hutchinsiæ, Nees, in part.)—Wet rocks, N. Eng. to S. C.; more common in the mountains.

3. LEJEÙNEA, Libert. (Pl. 24.)

Leaves decurrent at the folds, the lower lobe incurved and ventricose; underleaves usually present, entire or bifid. Archegonium with a slender persistent style, solitary on a usually very short branch; the perianth free from the involucral leaves, oval or oblong, terete or angular, variously carinate, cristate, or ciliate. Capsule globose, 4-cleft to the middle, the valves recurved. Spores large (40–50 µ broad), globose or oblong, tuberculate. Antheridia at the base of ordinary leaves or in the axils of the leaves of a spike-like branch.—Otherwise as Frullania. (Named for A.-L.-S. Lejeune, a French botanist.)

[*] Underleaves entire.

1. L. clypeàta, Sulliv. (Pl. 24.) Stems procumbent, somewhat pinnately branched, ¾–1´ long; leaves whitish-green, round-ovate, cellular-crenulate, deflexed; lower lobe flat, oblong-quadrate; underleaves round-quadrate; monœcious; involucral leaves larger than those of the stem, the perianth round-obovate, 2–3-carinate dorsally, 1-carinate ventrally, the keels rough. (L. calyculata, Tayl.)—On rocks and trees; common south and westward.

[*][*] Underleaves bifid; leaves entire.

2. L. serpyllifòlia, Libert, var. Americàna, Lindb. Stems long, somewhat branching, pale, pellucid and fragile; leaves rather remote, flat, opening from a basilar sac, scarcely decurved, obliquely roundish-ovate, obtuse, often slightly repand; underleaves about half as large, round-oval with a broad obtuse sinus and acute lobes; monœcious; the obovate-clavate perianth on a lateral branch. (L. cavifolia, Aust.)—On cedars, etc., Catskill Mts. (Cleve), Belleville, Ont. (Macoun), and southward; rather common.

3. L. lùcens, Tayl. Whitish, filiform, pinnately branched; leaves remote, rarely subimbricate, obliquely ovate-triangular, rounded or obtuse, semi-cordate at base; lower lobe ovoid, acute or apiculate; underleaves ½ as large as the lateral, round-oval, deeply bifid, the lobes broad-subulate; diœcious; involucral leaves rather longer, with lanceolate lobes; perianth scarcely emersed, broadly pyriform, 5-carinate. (L. cucullata, Sulliv.; not Nees.)—Near Cincinnati; moist rocks, Alleghany Mts. and southward (Sullivant). Minute and flaccid.

[*][*][*] Underleaves obsolete; leaves muriculate-denticulate.

4. L. calcàrea, Libert. Very minute; stems slender, loosely branching; leaves ovate, falcate-decurved, sinuate-complicate at base; monœcious; involucral leaves bifid, the divisions entire; perianth on a very short lateral branch, pyriform-clavate, acutely 5-angled, the margin echinate-muriculate. (L. echinata, Tayl.)—On rocks and roots of trees; rather common. (Eu.)

4. RÁDULA, Dumort. (Pl. 24.)

Leaves large, complicate-bilobed, incubous; lower lobe small, bearing root-hairs; underleaves none. Diœcious, rarely monœcious. Fruit usually terminal. Involucral leaves 2, slightly smaller than the cauline, 2-lobed; perianth tubular, compressed or nearly terete, truncate, entire or crenate. Calyptra pyriform, persistent. Capsule oval-cylindric. Elaters slender, free. Spores large, globose, minutely tuberculate. Antheridia in the ventricose bases of spicate leaves. (Radula, a scraper or spatula, in allusion to the form of the perianth.)

[*] Lower lobe subquadrate, barely incumbent on the stem.

1. R. complanàta, Dumort. Creeping, widely subpinnately branching; leaves imbricate, spreading, rounded, the lower lobe obtuse or acute; monœcious; perianth obconic, compressed, the mouth entire, truncate; antheridia in the bases of 2–3 pairs of strongly imbricate tumid leaves.—On rocks aud roots of trees; common. (Eu.)

2. R. obcónica, Sulliv. (Pl. 24.) Smaller, indeterminately branched; leaves somewhat remote, round-obovate, convex; monœcious; perianth clavate-obconic, obliquely truncate; antheridia axillary on short lateral branches rising near the terminal involucre.—On trees in cedar swamps, N. J. to Ohio.

[*][*] Lower lobe small, rounded, more or less transversely adnate.

3. R. tènax, Lindb. Stems brownish-green, rigid, tenacious; leaves remote, scarcely decurrent, obliquely elliptic-ovate, opaque, the cells round and strongly chlorophyllose; diœcious; the antheridial spike lateral below the keel of a leaf, long, linear, somewhat obtuse. (R. pallens, Sulliv.; not Gottsche.)—On rotten trunks, in the Catskill Mts., and southward, especially in the mountains.

5. PORÉLLA, Dill. (Pl. 24.)

Leaves large, incubous, complicate-bilobed; lower lobe ligulate, suberect; underleaves similar, decurrent at base, the apex entire. Diœcious. Fruit on a short lateral branch. Involucral leaves usually 4, 2-lobed, the margin ciliate or denticulate; perianth somewhat oval, compressed, bilabiate, incised or entire. Calyptra globose, persistent. Capsule globose, reddish, short-stalked. Elaters very numerous, 2–3-spiral, free. Spores large, rough. Antheridia solitary in the saccate bases of leaves, crowded in short spikes. (Name a diminutive of porus, an opening.)

[*] Leaves more or less remote; stems bipinnate.

1. P. pinnàta, L. Stems irregularly pinnate, fastigiate at the ends; leaves scarcely incubous, ovate-oblong, the rounded apex sometimes slightly decurved; lower lobe minute, flat, oblong, obtuse, as long but not half as wide as the flat, entire, ovate-rectangular, scarcely decurrent underleaves. (Madotheca Porella, Nees.)—On rocks and trees subject to inundation; common. (Eu.)

[*][*] Leaves mostly closely imbricate; stems mostly simply pinnate (or bipinnate in n. 2).

2. P. platyphýlla, Lindb. (Pl. 24.) Yellowish or fuscous-green; stems irregularly pinnate, often fastigiate at the ends; leaves obliquely ovate, more or less concave at base and the rounded upper margin curved upward aud undulate, mostly entire; lower lobe obliquely ovate, the margin strongly recurved, with an acute tooth at base; underleaves semicircular, with strongly reflexed margins. (Madotheca platyphylla, Dumort.)—On rocks and trees; common eastward. (Eu.)

3. P. Thùja, Lindb. Fuscous-green or blackish, somewhat regularly pinnate; leaves convex, closely appressed, obliquely round-ovate, the rounded apex decurved, more or less denticulate; lower lobe oblong, obtuse, with an acute tooth at base, longer but narrower than the quadrate underleaves, both with strongly recurved sparsely denticulate margins. (Madotheca Thuja, Dumort.)—On rocks and trees; more common westward. (Eu.)

4. P. dentàta, Lindb. Mostly fuscous-green, irregularly pinnate or subdichotomous; leaves more remote on the branches, obliquely round-ovate, the rounded summit slightly decurved, more or less denticulate; lower lobe decurrent, twisted, obliquely ovate, acute, with recurved undulate denticulate margin and a large acute tooth at base; underleaves twice as wide as the lower lobes, quadrate-oval, the undulate reflexed margin dentate, especially near the base. (Madotheca rivularis, Nees.)—Shaded rocks, Yellow Springs, Ohio (Sullivant). (Eu.)

5. P. Sullivántii, Underw. Stems strongly decurved at the ends in drying; leaves suberect, the straight ventral margin strongly involute toward the apex; cells large, punctate-stelliform; perianth broadly keeled beneath, the keel 2-angled. (Madotheca Sullivantii, Aust.)—Alleghany Mts. (Sullivant); rare.

6. PTILÍDIUM, Nees. (Pl. 24.)

Leaves incubous, complicate-bilobed, each lobe divided and lacerately ciliate; underleaves 4–5-lobed, ciliate. Diœcious. Fruit terminating short branches. Involucral leaves 2–4, 4-cleft; perianth terete, obovate, the mouth connivent, plicate, denticulate. Calyptra pyriform, coriaceous. Capsule ovate. Spores globose. Antheridia in the base of closely imbricated leaves. (Name a diminutive of πτίλον, a feather, from the fringed foliage.)

1. P. ciliàre, Nees. Stems crowded, subpinnate; fringes of the foliage long-setaceous. (Blepharozia ciliaris, Dumort.)—On rotten logs and stumps; common. (Eu.)

7. TRICHOCÓLEA, Dumort. (Pl. 24.)

Leaves succubous, 4–5-divided, and with the underleaves setaceously fringed. Diœcious. Fruit terminal, or axillary from the growth of innovations. Involucral leaves coalescent into an oblong truncate hairy tube, blended in our species with the calyptra; perianth none. Capsule oblong, its pedicel bulbous at base. Elaters free. Antheridia large, in the axils of leaves on terminal branches. (Name from θρίξ, hair, and κολεός, a sheath, from the hairy involucre.)

1. T. tomentélla, Dumort. Stems pinnately decompound, densely tufted, glaucous, 2–6´ long; leaves nearly uniform; underleaves subquadrate, as wide as the stem.—Among mosses in swamps; common. (Eu.)

T. Biddlecòmiæ, Aust., very imperfectly described from specimens collected in Urbana, Ohio, is said to be simply and rather distantly pinnate.

8. HERBÉRTA, S. F. Gray. (Pl. 24.)

Leaves large, incubous or nearly transverse, narrow, 3-ranked, the underleaves being scarcely smaller, cleft to or below the middle, the lobes acute. Diœcious. Fruit terminal on a long branch. Involucral leaves numerous, equitant; perianth ovate-subulate or narrowly fusiform, 3-angled, deeply 6–8-lobed. Calyptra small, obovate, deeply trifid. Capsule large, globose. Elaters free. Spores large, muriculate. Antheridia in the bases of leaves of a short terminal spike. (Named for William Herbert, an English botanist.)

1. H. adúnca, S. F. Gray. Stems long and slender, erect, brownish, nearly simple; leaves and underleaves almost alike, curved and one-sided, the lobes lanceolate. (Sendtnera juniperina, Sulliv.; not Nees.)—On rocks, Greenwood Mts., N. J., Catskill Mts., N. Y., and probably northward. (Eu.)

9. BAZZÀNIA, S. F. Gray. (Pl. 24.)

Leaves incubous, oblique, decurved, mostly truncate-tridentate; underleaves wider than the stem, mostly 3–4-toothed or crenate. Diœcious. Fruit on a short branch from the axil of an underleaf. Involucral leaves much imbricate, concave, orbicular or ovate, incised at the apex; perianth ovate-subulate or fusiform, somewhat 3-keeled. Calyptra pyriform or cylindric-oblong. Capsule oblong. Antheridial spikes from the axils of underleaves. (Named for M. Bazzani, an Italian Professor of Anatomy.)

1. B. trilobàta, S. F. Gray. (Pl. 24.) Creeping, dichotomous, proliferous; leaves ovate, the broad apex acutely 3-toothed; underleaves roundish-quadrangular, spreading, 4–6-toothed above; perianth curved, cylindric, plicate at the narrow apex and 3-toothed. (Mastigobryum trilobatum, Nees. M. tridenticulatum, Lindenb.)—Ravines, wet woods and swamps; common and variable. (Eu.)

2. B. defléxa, Underw. Stems forked or alternately branched; leaves strongly deflexed, cordate-ovate or ovate-oblong, falcate, the upper margin arcuate, the narrow apex 2–3-toothed or entire; underleaves roundish-quadrate, the upper margin bifid, crenate, or entire; perianth cylindric, arcuate, plicate above and denticulate. (Mastigobryum deflexum, Nees.)—On rocks in the higher mountains eastward. (Eu.)

10. LEPIDÒZIA, Dumort. (Pl. 24.)

Leaves small, incubous, palmately 2–4-cleft or -parted; underleaves similar, often smaller. Diœcious or rarely monœcious. Fruit terminal on short branches from the under side of the stem. Involucral leaves small, appressed, concave, 2–4-cleft; perianth elongated, ovate-subulate or narrowly fusiform, obtusely triangular above, entire or denticulate. Calyptra included, pyriform or oblong. Capsule oblong-cylindric. Spores minute, smooth or roughish. Antheridia large, pedicelled, solitary in the axils of 2-cleft spicate leaves. (Name from λεπίς, a scale, and ὄζος, a shoot, for the scale-like foliage.)

1. L. réptans, Dumort. (Pl. 24.) Creeping, pinnately compound, the branches often flagellate; leaves decurved, subquadrate, 3–4-cleft; involucral leaves ovate, truncate, unequally 4-toothed; perianth incurved, dentate.—On the ground and rotten wood, N. J., and common northward. (Eu.)

2. L. setàcea, Mitt. Leaves deeply 2–3-cleft or -parted, incurved, the lobes subulate, formed of a somewhat double series of cells; underleaves similar; perianth ciliate. (Jungermannia setacea, Web.)—On the ground and rotten wood; common. Resembling the next in its leaves, but smaller and brownish. (Eu.)

11. BLEPHARÓSTOMA, Dumort. (Pl. 25.)

Leaves transverse or slightly incubous, 3–4-parted, the divisions capillary; underleaves smaller, mostly 2–3-parted. Diœcious or monœcious. Fruit terminal. Involucral leaves numerous, verticillate, deeply 4-cleft; perianth exserted, pyriform-cylindric, laciniate. Calyptra short, oblong, bilabiate. Capsule cylindric-oblong. Elaters large, very obtuse. Spores large, smooth. Antheridia solitary in the axils of leaf-like bracts. (Name from βλέφαρον, an eyelid, and στόμα, mouth, in allusion to the fringed orifice of the perianth.)

1. B. trichophýllum, Dumort. Flaccid, branched, creeping; leaf-divisions straight, spreading, each composed of a single row of cells; perianth ovate-cylindric. (Jungermannia trichophylla, L.)—On the ground and rotten wood. Minute, light green. (Eu.)

12. CEPHALÒZIA, Dumort. (Pl. 23.)

Leaves mostly succubous, chiefly 2-lobed, the margins uniformly plane or subincurved; underleaves smaller, often wanting except on fruiting branches. Branches from the under side of the stem. Monœcious or diœcious. Involucral leaves numerous, capitate, 3-ranked, usually 2-lobed; perianth long, triangular-prismatic, the constricted mouth variously dentate. Calyptra small. Capsule somewhat oblong. Elaters free. Spores minute. Antheridia in the base of inflated spicate leaves. (Name from κεφαλή, head, and ὄζος, bud, for the capitate involucre.)

§ 1. CEPHALOZIA proper. Perianth more or less 3-angled or 3-carinate; leaf-cells large (mostly 25–50 µ broad); plants mostly medium-sized.

[*] Underleaves rarely present except on fruiting branches.

1. C. Virginiàna, Spruce. Without runners, usually pale; leaves small, obliquely round-ovate, acutely 2-lobed nearly to the middle; cells quadrate-hexagonal, opaque; diœcious, rarely monœcious; involucral leaves round-quadrate, with slender acuminate lobes; perianth large, widest above the middle, unequally ciliolate; capsule large, long-exserted; antheridial spike long. (C. catenulata of authors; not Huebn.)—On rotten wood or swampy ground, N. Eng. to Va., and southward.

2. C. multiflòra, Spruce. (Pl. 23.) Often subpinnate, without runners, pale green; leaves small, round-rhombic, decurrent, bifid {1/3} their length; cells quadrate-hexagonal, pellucid; diœcious; inner involucral leaves 3–4 times as long as the outer; perianth linear-fusiform, 3-plaited when young, triangular only above when mature, ciliate or toothed, fleshy; calyptra fleshy, oval-globose; capsule rather short-pedicelled; spores cinnamon-color.—On the ground and rotten wood; common. (Eu.)

3. C. pléniceps, Underw. Stems very short, branching, densely cespitose, pale green or whitish; leaves thick, orbicular, strongly concave, subclasping but not decurrent, bifid {1/3} their length, the acute lobes incurved and strongly connivent; involucral leaves oblong, palmately 2–4-cleft, the ventral like the underleaves; perianth large, oblong-cylindric, obtusely angled, the plicate mouth denticulate. (Jungermannia pleniceps, Aust.)—Among Sphagnum in the White Mts. (Oakes).

4. C. bicuspidàta, Dumort. Prostrate or assurgent, cespitose, usually greenish or reddish, with runners; lower leaves small and distant, the upper larger, round-ovate, cleft nearly to the middle, the lobes ovate-lanceolate and acute, the lower lobe narrower and acuminate; cells large, pellucid; monœcious; involucral leaves about 3 pairs, the innermost nearly three times as long as the outer, cleft ½ their length; perianth four times as long as the leaves, linear-prismatic or fusiform, thin, denticulate or ciliate; capsule cylindric-oblong; spores purple. (Jungermannia bicuspidata, L.)—On the ground, mountains of N. Eng., N. Y., and N. J. (Eu.)

5. C. curvifòlia, Dumort. Slender, rarely forked, without runners, greenish, reddish, or often purple; leaves imbricate, ascending, obovate, concave, semicordate at base, lunately bifid below the middle, the lobes incurved or hooked; cells small, quadrate; monœcious or diœcious; involucral leaves complicate, the lobes subovate, spinulose-denticulate; perianth large, rose-purple, triquetrous, the wide mouth ciliate; calyptra thin; capsule oblong-globose. (Jungermannia curvifolia, Dicks.)—On rotten logs in swamps, etc.; common. (Eu.)

[*][*] Underleaves usually present; leaves rarely subimbricate.

6. C. flùitans, Spruce. Stems 2–3´ long, loosely creeping, with short thick runners; leaves large, ovate-oblong, lobed to near the middle, the lower lobe larger, lanceolate, obtuse; cells large, mostly hexagonal; underleaves linear, appressed; diœcious; involucral leaves cleft to the middle; perianth oval-cylindric, nearly entire; calyptra short, pyriform; capsule oblong; spores small, minutely tuberculate; antheridia globose, pedicelled, solitary in the axils.—In bogs, on mosses or partly floating; rare. (Eu.)

§ 2. CEPHALOZIÉLLA. Perianth 3–6-angled; leaf-cells small (14–20 µ broad); plants small, often minute; underleaves present in n. 9.

7. C. divaricàta, Dumort. Sparingly branched, without runners; leaves very small, cuneate or round-quadrate, the ovate-triangular lobes acute; cells pellucid or subopaque; involucral leaves larger, the lobes acute, denticulate; perianth linear or narrowly fusiform, prismatic, denticulate or subentire; capsule oblong-globose, long-exserted. (Jungermannia divaricata, Smith.)—Dry rocks and sand, pine barrens of N. J., and northward. (Eu.)

8. C. Macoùnii, Aust. Slender, much branched, dark green; leaves scarcely broader than the stem, wide-spreading, bifid with a broad or lunate sinus, the broad-subulate lobes mostly acute; cells subquadrate, somewhat pellucid; diœcious; involucral leaves appressed, 2–3-lobed, irregularly spinulose; perianth small, whitish, obovate or ovate-fusiform, obtusely 3-angled, setulose or ciliate.—Rotten logs, mountains of N. Eng., and northward (Austin, Macoun).

9. C. Sullivántii, Aust. Stems 3–6´´ long, fleshy, rootlets numerous; fertile branches suberect, clavate; leaves imbricate, often narrower than the stem, subquadrate-ovate, more or less serrate, the sinus and lobes subacute; diœcious; involucral leaves 3, erect, free; perianth broadly oval or subobovate, obtusely and sparingly angled, the apex slightly plicate, the mouth connivent, dentate, sometimes narrowly scarious; capsule oval.—On rotten wood, N. J., Ohio, and Ill.; rare. Our smallest species.

13. ODONTOSCHÍSMA, Dumort. (Pl. 24.)

Leaves succubous, ovate or roundish, entire or retuse, rarely bidentate; underleaves minute, sometimes obscure or wanting. Diœcious or sometimes monœcious. Fruit terminal on a short branch from the lower side of the stem. Involucral leaves few, 3-ranked, bifid or rarely 3–4-cleft; perianth large, triangular-fusiform, ciliate or dentate. Calyptra membranous. Capsule cylindric-oblong. Antheridia in small whitish spikes on the under side of the stem. (Name from ὀδούς, a tooth, and σχίσμα, a cleft, alluding to the perianth.)

1. O. Sphágni, Dumort. (Pl. 24.) Leaves spreading or ascending, ovate, rounded or oblong, entire or retuse, subconcave; underleaves mostly wanting; perianth 3–6 times longer than the leaves, subulate-fusiform, laciniate or ciliate. (Sphagnœcetis communis, Nees.)—Among mosses, N. J. to Ill., and southward. (Eu.)

2. O. denudàta, Lindb. Stems densely rooting, somewhat leafless at base, flagellate, branching above; leaves spreading, broadly ovate, entire; underleaves broadly oval, entire or subdenticulate; perianth close-connivent above, at length bursting irregularly.—On rotten wood, Canada to Ohio, and south along the mountains. (Eu.)

14. KÁNTIA, S. F. Gray. (Pl. 24.)

Leaves large, incubous, flat or convex, entire or retuse; underleaves small, roundish, the apex entire, retuse or bifid. Diœcious or monœcious. Involucre pendulous, subterranean, clavate or subcylindric, fleshy, hairy, attached to the stem by one side of its mouth. Calyptra membranous, partly adnate to the involucre. Capsule cylindric, the valves spirally twisted. Spores minute, roughish. Antheridia solitary in the reduced leaves of short lateral branches. (Name from J. Kant, a physician at The Hague.)

1. K. Trichómanis, S. F. Gray. (Pl. 24.) Creeping, without ventral runners; leaves pale green, imbricate, spreading, roundish-ovate, obtuse. (Calypogeia Trichomanis, Corda.)—On the ground and rotten logs; very common. (Eu.)—Var. rivulàris, Aust. Leaves dusky green or blackish, more scattered, flaccid; cells large. N. J. (Austin.)—Var. ténuis, Aust. Very slender, innovate-branching; leaves smaller, especially above, dimidiate-ovate or subfalcate, subdecurrent. Southern N. J. (Austin).

2. K. Sullivántii, Underw. Prostrate, with ventral runners; leaves flat, subcontiguous or imbricate, obliquely round-ovate, minutely 2-toothed with a lunulate sinus, abruptly decurrent; cells large, uniform; underleaves minute, the upper orbicular, bifid, the lower twice 2-lobed, the primary lobes round-quadrate, divaricate, the secondary ovate or subulate. (Calypogeia Sullivantii, Aust.)—Delaware Water Gap, N. J. (Austin).

15. SCAPÀNIA, Dumort. (Pl. 24.)

Leaves complicate-bilobed, the upper lobe smaller, the lower succubous; margins entire or dentate or ciliate; underleaves none. Diœcious. Fruit terminal. Involucral leaves like the cauline but more equally lobed; perianth obovate, dorsally compressed, bilabiate, the mouth truncate, entire or toothed, decurved. Capsule ovate. Elaters long, attached to the middle of the valves. Antheridia 3–20, in the axils of small saccate leaves, which are scarcely imbricate or crowded into terminal heads. (Name from σκαπάνιον, a shovel, from the form of the perianth.)

[*] Leaf-lobes somewhat equal.

1. S. subalpìna, Dumort. Leaves equidistant, imbricate, cleft nearly to the middle, the roundish obtuse lobes denticulate on the outer margin; perianth much exceeding the involucral leaves, obovate from a narrow base, denticulate.—Mountains of N. Eng. (Oakes, Austin); L. Superior (Gillman, Macoun). (Eu.)

2. S. glaucocéphala, Aust. Stems short, cespitose, creeping or ascending, subsimple, with numerous offshoots; leaf-lobes broadly ovate, entire, mostly obtuse and apiculate; involucral leaves sometimes denticulate; perianth small, subcuneate, entire. (Jungermannia glaucocephala, Tayl.; S. Peckii, Aust.)—On rotten wood, N. Eng. to N. Y. and Canada.

[*][*] Lower lobe about twice the size of the upper, except near the summit.

[+] Leaves broader than long; upper lobes rounded or blunt.

3. S. undulàta, Dumort. (Pl. 24.) Ascending or erect, slightly branched; leaves lax, spreading, entire or ciliate-denticulate, the lobes round-trapezoidal, equal at the summit of the stem; perianth oblong-incurved, nearly entire, twice as long as the outer involucre.—In woods, damp meadows, and rills; common, especially in mountain districts.—Var. purpùrea, Nees; a form with long lax stems and rose-colored or purplish leaves. (Eu.)

4. S. irrígua, Dumort. Creeping; leaves somewhat rigid, repand, deeply lobed; lobes rounded, submucronate, the lower appressed, the upper convex with incurved apex; perianth ovate, denticulate. (S. compacta, var. irrigua, Aust.)—Wet places, N. J., Catskill Mts., mountains of N. Eng., and northward. (Eu.)

[+][+] Leaves longer than broad; upper lobes more or less acute.

5. S. nemoròsa, Dumort. Rather stout, flexuose, creeping at base; leaves rather distant, decurrent on both sides, ciliate-dentate, the lower lobe obovate, obtuse, slightly convex, the upper cordate, acute, concave; perianth densely ciliate; capsule large, roundish-ovate, reddish-brown. (S. breviflora, Tayl.)—On rocks, etc., in swamps and rills; common and variable. (Eu.)

6. S. Oakèsii, Aust. Leaves obovate, somewhat spreading, often deflexed, closely complicate, convex, the lower lobe coarsely dentate, and with deep purple spur-like teeth on the keel, the upper roundish and less dentate; perianth usually dentate.—White Mts. (Oakes, Austin).

[*][*][*] Lower lobes 3–4 times the size of the upper.

7. S. exsécta, Aust. Ascending; leaves subcomplicate, entire, the lower lobe ovate, acute or bidentate, concave, the upper small and tooth-like; involucral leaves 3–5-cleft; perianth oblong, obtuse, plicate. (Jungermannia exsecta, Schmidel.)—High mountains, far northward; rare.—Perhaps better retained in Jungermannia. (Eu.)

8. S. umbròsa, Dumort. Stems short, decumbent, slightly branched; leaf-lobes ovate, acute, serrate; perianth incurved, naked at the mouth.—White Mts.; rare.—The tips of the shoots are frequently covered with a dark mass of gemmæ. (Eu.)

16. DIPLOPHÝLLUM, Dumort. (Pl. 25.)

Leaves rather narrow, complicate-bilobed, the lobes subequal or the upper smaller, the lower succubous; underleaves none. Fruit terminal. Involucral leaves few. Perianth cylindrical, scarcely or not at all compressed, pluriplicate, denticulate. (Name from διπλός, double, and φύλλον, leaf, on account of the folded 2-lobed leaves.)

1. D. álbicans, Dumort., var. taxifòlium, Nees. Stems ascending, almost rootless; leaves closely folded, subdenticulate, with a rudimentary pellucid line near the base or none, the lobes obtuse or acutish, the lower oblong-scymitar-shaped, the upper smaller, subovate; perianth ovate, plicate. (Jungermannia albicans and J. obtusifolia of Sulliv.; not of L. and Hook.)—Under rocks in mountain ravines and on the ground. (Eu.)—The typical form occurs in N. Scotia, distinguished by a broad pellucid median line in both lobes.

17. GEÓCALYX, Nees. (Pl. 23.)

Leaves succubous, bidentate; underleaves 2-cleft, with linear divisions. Fruit lateral, pendent. Involucre simple, fleshy, saccate, oblong, truncate, attached to the stem by one side of the mouth. Calyptra membranous, partly adnate to the involucre. Capsule oblong. Elaters free. Antheridia in the axils of small leaves on spike-like lateral branches. (Name from γέα, the earth, and κάλυξ, a cup, from the subterranean involucres.)

1. G. gravèolens, Nees. Leaves ovate-quadrate, 2-toothed, light green; underleaves oval-lanceolate, cleft to the middle.—On the ground, and rotten logs; not rare. (Eu.)

18. LOPHOCÓLEA, Dumort. (Pl. 23.)

Leaves succubous, dorsally decurrent, obliquely ovate-oblong, broadly truncate or bidentate; underleaves smaller, more or less quadrate, bifid or with 4–8 capillary lobes. Diœcious or monœcious. Fruit terminal on the main stem or primary branches. Involucral leaves 2–4, large, often spinulose; perianth triangular-prismatic, 3-lobed, ciliate or laciniate. Calyptra short, obovate, at length lacerate above. Capsule oblong-globose. Antheridia mostly solitary in or near the base of ordinary leaves. (Name from λόφος, a crest, and κολεός, a sheath, from the crested perianth.)

[*] Underleaves mostly bifid (or 3–4-cleft in n. 1); divisions mostly entire.

1. L. bidentàta, Dumort. Stems 1–2´ long, procumbent, sparsely branching; leaves pale green, ovate-triangular, acutely 2-toothed, the teeth oblique with a lunulate sinus; monœcious; perianth oblong-triangular, lacinate; antheridia 2–3 in a cluster, axillary.—On rocks in shady rills; not common. (Eu.)

2. L. Austìni, Lindb. Creeping; leaves uniformly deeply lobed, the lobes and usually the sinus acute; underleaves comparatively small, the lobes subulate; cells small; monœcious; antheridia solitary in the upper axils. (L. minor, Aust.; not Nees.)—On roots of trees in woods (Austin). Imperfectly known.

3. L. Macoùnii, Aust. Stems very short, prostrate, ascending at the apex, densely radiculose; leaves suberect, ovate-subquadrate, 2-lobed with obtuse lobes and sinus, or retuse or often entire; underleaves light pink, deeply bifid, the setaceous lobes spreading-incurved; monœcious; involucral leaves somewhat oblong, repandly 2–4-toothed at the apex; perianth subobovate, slightly angled.—On logs, Little Falls, N. Y. (Austin); Ont. (Macoun).

4. L. mìnor, Nees. Diffusely branching; leaves pale green, oval-subquadrate, expanded, convex, slightly rigid, equally and acutely bifid with a lunate sinus; underleaves {1/3} as large, deeply bifid, the lanceolate lobes acuminate; diœcious; involucral leaves like the cauline; perianth obtusely triangular-plicate at the apex. (L. crocata, Aust.; not Nees.)—On the ground and dry rocks in limestone regions (Austin). (Eu.)

[*][*] Divisions of the underleaves more or less dentate.

5. L. heterophýlla, Nees. (Pl. 23.) Stems short, creeping or ascending, much branched; leaves ovate-subquadrate, entire, retuse and bidentate on the same stem; underleaves large, 2–3-cleft; involucral leaves lobed and dentate; perianth terminal, the mouth crested.—On the ground and rotten logs in woods and swamps; very common. (Eu.)

6. L. Hàllii, Aust. Creeping, very slightly rooting; leaves subvertical, oblong, cleft nearly to the middle with obtuse sinus and erect mostly obtuse lobes; lower underleaves small, subequally 2-parted with an obtuse sinus, the upper ones larger, with a single tooth on each side or palmately 3–4-parted, the apical sublanceolate and narrowly bifid.—On the ground, Ill. (Hall).

19. CHILOSCỲPHUS, Corda. (Pl. 23.)

Leaves succubous, dorsally decurrent, mostly rounded and entire; underleaves rooting at the base, usually deeply 2-cleft. Fruit terminal on a very short lateral branch. Involucral leaves 2–6, the outer smaller, the inner variously cut; perianth small, obconic or campanulate, 3-angled and 3-lobed only at the apex, the lobes usually spinose. Calyptra fleshy, subglobose or clavate. Capsule oblong-globose. Antheridia in the saccate bases of stem-leaves. (Name from χεῖλος, a lip, and σκύφος, a bowl, from the form of the perianth.)

[*] Underleaves 4-parted.

1. C. ascéndens, Hook. & Wils. (Pl. 23.) Prostrate; leaves large, pale green, ascending, roundish-oblong, slightly emarginate; involucral leaves two, 2-cleft; perianth 2–3-lobed, the lobes long and irregularly lacerate-toothed.—On rotten logs; rather common.

[*][*] Underleaves bifid.

2. C. palléscens, Dumort. Procumbent, creeping; leaves flattened, ovate-subquadrate, obtuse or retuse; underleaves ovate, distant, free; involucral leaves two, 2-toothed; perianth deeply trifid, the lobes spinose-dentate, mostly shorter than the conspicuous calyptra.—Mountains of N. Eng. (Oakes).

3. C. polyánthos, Corda. Procumbent, creeping; leaves subascending, ovate-subquadrate, truncate or subretuse; underleaves ovate-oblong, distant, free; involucral leaves 2, slightly 2-toothed; perianth 3-lobed, the short lobes nearly entire, shorter than the calyptra.—Var. rivulàris, Nees. Larger, more branching, succulent; leaves mostly rounded above; underleaves often divided in halves or wanting.—On the ground among mosses or on rotten logs, common; the variety in shaded rills or still ponds. (Eu.)

20. PLAGIOCHÌLA, Dumort. (Pl. 24.)

Leaves large, succubous, rounded or truncate above, dentate or spinose or rarely entire, the dorsal margin reflexed; underleaves usually none. Diœcious or monœcious. Fruit terminal, or axillary by the growth of offshoots. Involucral leaves larger than the cauline; perianth laterally compressed, erect or decurved, obliquely truncate and bilabiate, the lobes entire or ciliate-dentate. Capsule thick, oval. Elaters attached to the middle of the valves. Antheridia oval, 2–3 in the axils of spicate leaves. (Name from πλάγιος, oblique, and χεῖλος, lip, from the form of the perianth.)

[*] Underleaves 2–3-cleft, fugacious.

1. P. porelloìdes, Lindenb. Branches ascending; leaves subimbricate, convex-gibbous, round-obovate, the uppermost repand-denticulate, the rest entire, the dorsal margin reflexed; perianth terminal, oblong-ovate, the mouth compressed, denticulate.—Among mosses in swamps and river-bottoms; common.

2. P. interrúpta, Dumort. (Pl. 24.) Prostrate, horizontally branched, copiously rooting; leaves imbricate, horizontal, oval, entire or slightly repand; underleaves lanceolate; perianth terminal, broadly obconic, the mouth compressed, repand-crenulate. (P. macrostoma, Sulliv.)—Moist banks and decayed logs, N. Eng., Ohio, and northward. (Eu.)

[*][*] Underleaves wanting.

3. P. spinulòsa, Dumort. Creeping, branches ascending; leaves remote, obliquely spreading, obovate-cuneate, the dorsal margin reflexed, entire, the ventral and apex spinulose-toothed; perianth rounded, at length oblong, the mouth spinulose.—Shaded rocks in mountain regions; rare. (Eu.)

4. P. asplenoìdes, Dumort. Branched, creeping or ascending; leaves subimbricate, obliquely spreading, round-obovate, entire or denticulate, the dorsal margin reflexed; perianth much exceeding the involucral leaves, oblong, dilated at the truncate or ciliate apex.—In rocky rivulets; common. (Eu.)

21. MÝLIA, S. F. Gray. (Pl. 25.)

Leaves succubous, semi-vertical, circular, or ovate and pointed; underleaves subulate. Diœcious. Fruit terminal or pseudaxillary. Involucral leaves 2, clasping; perianth ovate-oblong, laterally compressed above a subterete base, the apex at length bilabiate, denticulate. Capsule ovate, coriaceous. Elaters free. Antheridia 2 in the axils of bracts clustered near the apex of distinct branches. (Name from Mylius, an early botanist.)

1. M. Taylòri, S. F. Gray. Stems erect, nearly simple, radiculose; leaves large, convex, orbicular, entire, purplish; cells large; underleaves lance-subulate, entire or subdentate; perianth terminal, oval; calyptra finally long-exserted. (Jungermannia Taylori, Hook.)—Wet rocks, high mountains of N. Eng. and N. Y. (Eu.)

22. HARPÁNTHUS, Nees. (Pl. 23.)

Leaves succubous, semi-vertical, ovate, emarginate; underleaves connate with the leaves, ovate or lanceolate, 1-toothed at base. Diœcious. Fruit on short shoots from the axils of the underleaves, finally sublateral. Involucral leaves 2 or 4. Perianth terete, the lower half thickened. Calyptra fleshy, confluent with the perianth for {2/3} its length. Capsule oval. Antheridia 1 or 2 in the axils of bracts terminal on slender branches. (Name from ἅρπη a sickle, and ἄνθος, flower.)

1. H. scutàtus, Spruce. Stems filiform, decumbent, usually simple; leaves smaller at the base and apex of the stems, roundish-ovate, concave, sharply bidentate, the apex lunate or acute; underleaves large, acuminate, involucral leaves two, 2–3-cleft, the upper adnate to the perianth; perianth ovate, becoming obovate, obscurely 3–4-plicate, splitting above on one side; capsule deep brown. (Jungermannia scutata, Weber.)—On rotten logs in damp places; common. (Eu.)

H. Flotoviànus, Nees. (Pl. 23.) Stems flexuous, procumbent, mostly unbranched; leaves ovate-orbicular, horizontal, the apex contracted and emarginate with a shallow sinus; underleaves large, ovate or lanceolate, obliquely inserted, entire or more often toothed on one or both sides near the middle; diœcious; perianth subcylindric, slightly sickle-shaped, the mouth pointed at first, notched on one side and finally crenulate; antheridia elliptic, single in the base of swollen leaves. (Pleuranthe olivacea, Tayl.)—"North America" (Drummond), but not collected recently; certainly extralimital.

23. LIOCHLÆ̀NA, Nees. (Pl. 25.)

Leaves succubous, ovate-oblong, entire or slightly retuse; underleaves none. Diœcious or monœcious. Involucral leaves 2 or 4, like the cauline; perianth pyriform, becoming cylindric, incurved, abruptly rounded at the summit, the minute orifice prominently ciliolate. Capsule oblong, long-exserted. Elaters attached to the middle of the valves. Spores minute, globose. Antheridia in the axils of ordinary leaves. Archegonia 5–12. (Name from ληῖος, smooth, and χλαῖνα, a cloak, referring to the perianth.)

1. L. lanceolàta, Nees. Closely creeping, branched; leaves sometimes decurrent; involucral leaves vertical; perianth at right angles with the stem; monœcious.—On banks and rotten logs; not rare. (Eu.)

24. JUNGERMÁNNIA, Micheli. (Pl. 25.)

Leaves succubous, rarely subtransverse, entire, lobed or dentate, the margins never recurved; underleaves present or none. Diœcious or monœcious. Fruit terminal. Involucral leaves 4 or fewer, like the cauline or more incised, free; perianth laterally compressed or terete, usually 3–10-carinate, the usually small mouth entire or toothed. Calyptra oval-pyriform. Capsule globose or oblong, rarely cylindric. Spores minute, smooth or roughish. Archegonia 8–70. (Named for L. Jungermann, a German botanist of the 17th century.)

§ 1. JUNGERMANNIA proper. Leaves orbicular or ovate, entire or barely retuse; underleaves none (very small in n. 1).

1. J. Schràderi, Martius. (Pl. 25.) Creeping, flexuous; leaves round-elliptic, entire, ascending; underleaves broadly subulate, not apparent on old stems; involucral leaves large, elongated, the inner smaller and more or less laciniate; perianth oval-obovate, ascending.—On the ground and rotten logs; common. (Eu.)

2. J. sphærocárpa, Hook. Stems creeping, the tips ascending, subsimple, greenish; leaves semi-vertical, rather rigid, orbicular, obliquely spreading, decurrent dorsally, pale green; involucral leaves separate; perianth exserted, obovate-oblong, the mouth 4-cleft; capsule globose.—Mountains of N. Eng. (Austin); rare. (Eu.)

3. J. pùmila, With. Stems creeping, the tips somewhat ascending, subsimple, rooting, pale; leaves ascending, ovate, obtuse, concave, entire; involucral leaves like the cauline, erect; perianth terminal, fusiform, plicate above and denticulate; capsule oval.—On shaded rocks along rivulets, Closter, N. J. (Austin). (Eu.)

§ 2. LOPHÒZIA. Leaves roundish or subquadrate, bidentate, bifid, or sometimes 3–5-cleft; underleaves none, or small and mostly 2-parted; perianth usually strongly plicate.

[*] Underleaves present.

[+] Leaves bifid or 2-lobed.

4. J. Gillmàni, Aust. Stems short, densely cespitose, prostrate, strongly radiculose; leaves vertical, round-ovate, subconcave, bifid, the lower leaves with usually acute sinus and lobes, the upper much larger with rounded lobes and obtuse sinus; underleaves entire or the broader bifid; perianth without involucral leaves, dorsal, sessile, obovate, subgibbous, ciliate, at length much incised.—In a sandstone cave, Traine Island, L. Superior (Gillman).

5. J. Wattiàna, Aust. Stems rather thick, 2–4´´ long, fragile, subflexuose, strongly radiculose; leaves subvertical or spreading, subovate, concave, emarginately 2-lobed, the lobes acute or the upper obtuse; underleaves somewhat obsolete, hair-like or subulate, incurved; involucral leaves little larger, less deeply lobed; perianth terminal, small, ovate-gourd-shaped, whitish, ciliate.—On the ground, northern shore of L. Superior (Macoun).

[+][+] Leaves 3–5-cleft.

6. J. barbàta, Schreb. (Pl. 25.) Procumbent, sparingly branched; leaves roundish-quadrate, with obtuse, acute, or mucronulate lobes and obtuse undulate sinuses; underleaves broad, entire or 2-toothed, sometimes obsolete; perianth ovate, plicate-angled toward the apex, denticulate.—On rocks in mountain regions; common. (Eu.)

Var. attenuàta, Martius. Ascending, with numerous offshoots; stem-leaves semi-vertical, obliquely spreading, roundish, acutely 2–4-toothed, those of the shoots closely imbricate, premorsely 2–4-denticulate; involucral leaves two, 3-toothed; perianth oblong.—In similar localities. (Eu.)

7. J. setifórmis, Ehrh. Erect or ascending, dichotomous; leaves toothed at base, 3–4-cleft, the lobes ovate-oblong, acute, channelled; underleaves ciliate-dentate at base, deeply bifid, the divisions lanceolate, acuminate; involucral leaves more toothed than the cauline; perianth terminal, oval, plicate.—Alpine summits of N. H. (Oakes). (Eu.)

[*][*] Underleaves wanting.

[+] Leaves 2-toothed; involucral leaves 2–4-cleft.

8. J. alpéstris, Schleich. Stems creeping, crowded, bifid-branching, the ends ascending; leaves semi-vertical, ovate subquadrate, obliquely toothed, the teeth unequal, acute or mucronulate, distant; involucral leaves wider, 2–3-cleft; perianth twice as long, oblong, smooth, the mouth complicate; capsule oval.—Alpine region of N. H. (Oakes). (Eu.)

9. J. ventricòsa, Dicks. Stems dense, close-creeping, branching from beneath; leaves semi-vertical, subquadrate, mostly flat, broadly and acutely emarginate-bidentate, often bearing globules; involucral leaves larger, round, erect-spreading, 3–4-cleft, subdentate; perianth ovate, inflated, narrowly complicate above; capsule oval.—On the ground and rotten wood in the mountains, and far northward; common. (Eu.)

10. J. Wallrothiàna, Nees. Minute, blackish; stems creeping, strongly rooting, subsimple; leaves clasping, semi-vertical, closely imbricate, ovate-quadrate, concave, obtusely bidentate with an obtuse sinus, or acute in the upper leaves; involucral leaves larger, erect, connate at base, 3-toothed, wavy-plicate; perianth oval-cylindric, plicate and subdentate, pellucid, reddish below.—On coarse sand in the White Mts. (Oakes). (Eu.)

[+][+] Leaves bifid or 2-lobed, the ventral lobe often inflexed or subcomplicate; involucral leaves merely toothed, except in n. 11.

11. J. láxa, Lindb. Widely creeping, mostly simple, usually purplish-black; leaves imbricate, or distant on the erect fertile stems, 2–3-lobed, the lobes obtuse, wavy; cells very large, lax; involucral leaves 2, wide, short, cristate-undulate, obtusely many-lobed; perianth exserted, long-clavate, sub-plicate above, minutely ciliate. (J. polita, Aust.; not Nees.)—Among Sphagnum near Closter, N. J. (Austin).

12. J. excìsa, Dicks. Stems closely creeping, short, subsimple, rather rigid; leaves semi-vertical, erect-spreading, pellucid, roundish, with straight acute lobes and deep obtuse sinus; involucral leaves erect, quadrate, usually 4–5-toothed; perianth erect, oblong, pale, banded and spotted with pink, plicate above, irregularly denticulate.—Sterile grounds in open woods; common. (Eu.)

Var. críspa, Hook. Leaves round-quadrate, closely imbricate, deeply and obtusely 2–3-cleft; involucral leaves 3–4-cleft, connate at base, subserrate. (J. intermedia, Lindenb.)—In crevices of rocks, N. Y. and N. J. (Austin). (Eu.)

13. J. incìsa, Schrad. Stems thick, rooting, closely creeping or ascending; leaves crowded, semi-vertical, complicate, subquadrate, 2–6-cleft, the acute lobes unequal, more or less spinulose-dentate; involucral leaves similar, more plicate and dentate, free; perianth short, oval or obovate, plicate above, denticulate.—On rotten wood in the mountains, and northward. (Eu.)

§ 3. SPHENÓLOBUS. Leaves 2-lobed, subtransverse, complicate-concave; underleaves none; involucral leaves 2–3-cleft. (Verging toward Marsupella on one side and Diplophyllum on the other.)

14. J. Michaùxii, Weber. Stems ascending, flexuous by repeated innovations below the summit; leaves crowded, subvertical, erect-spreading, subsaccate at base, subquadrate, bifid with straight acute lobes and a narrow sinus; involucral leaves similar, the outer serrulate, the inner smaller; perianth ovate-subclavate, obtuse, plicate above, fringed.—Fallen trunks, mountains of N. Y. and N. Eng.; common. (Eu.)

15. J. minùta, Crantz. Rootless; leaves cleft ¼–½ their length, the lobes ovate, subequal, acute or obtuse, entire, or gemmiparous ones subdentate; involucral leaves trifid; perianth oval-oblong or subcylindric.—On rocks in high mountain regions, and northward. (Eu.)

16. J. Helleriàna, Nees. (Pl. 25.) Creeping, entangled; leaves spreading, subascending, cleft {1/3}–½ their length, the lobes equal, acute, entire or serrate; involucral leaves 2–3-cleft, spinulose serrate; perianth ovate, the mouth contracted.—On rotten wood, N. Y., N. Eng., and northward. (Eu.)

§ 4. GYMNOCÓLEA. Leaves 2-lobed; underleaves none; involucral leaves like the cauline; perianth pedunculate, denticulate.

17. J. inflàta, Huds. (Pl. 25.) Procumbent or ascending, loosely radiculose, branching; leaves semi-vertical, roundish-elliptic, inequilateral, the sinus and unequal lobes obtuse; perianth terminal or at length dorsal, oval or pyriform, smooth, the mouth connivent; capsule oblong.—On sterile ground and rocks, N. J. (Austin), and northward in the mountains. (Eu.)

25. MARSUPÉLLA, Dumort. (Pl. 23.)

Stems dorsally compressed, with rootlets at the base and often producing somewhat leafless runners. Leaves transverse, complicate-bilobed; involucral leaves 2 or 4, connate with the perianth. Perianth tubular or oval, subcompressed parallel to the base of the leaves. Elaters free. Spores round, rufous (in our species). Antheridia mostly terminal. (Name a diminutive of marsupium, a pouch, from the form of the perianth.)

1. M. sphacelàta, Dumort. Stems erect, subflexuous, pale brown; leaves rather distant, concave, obovate to obcordate, somewhat clasping, the sinus narrow; diœcious; involucral leaves larger than the cauline, cordate; perianth free at the apex, with 4–5 broad acute teeth; antheridia 1–3, in short terminal spikes.—Wet rocks, mountains of N. Eng. to N. J., and southward. (Eu.)

2. M. emarginàta, Dumort. (Pl. 23.) Stems simple or innovating at the summit, rigid, somewhat thickened upward; leaves usually broader than long, round-cordate or subquadrate, lobes obtuse or mucronate, sinus acute; diœcious; involucral leaves 4–8, usually larger, more deeply and acutely emarginate; perianth urceolate, the closed apex splitting into 4–5 triangular lobes; antheridia 2–3, oval, axillary in terminal spikes. (Sarcoscyphus Ehrharti, Corda.)—On wet rocks, chiefly in mountain rivulets, N. Y. and N. Eng. Floating forms are longer with distant leaves. (Eu.)

3. M. adústa, Spruce. Stems minute, clavate; leaves (5–8 pairs) imbricate, round or broadly ovate from a sheathing base, acutely lobed with angular sinus; monœcious; perianth included, campanulate, crenate becoming irregularly lobed; spores punctate; antheridia 1 or 2, oval, in the axils of the lower involucral leaves. (Gymnomitrium adustum, Nees.)—Alpine region of the White Mts. (Oakes, Austin). (Eu.)

26. NÁRDIA, S. F. Gray. (Pl. 25)

Stems laterally compressed, usually without runners. Leaves succubous, subconcave or flat, the apex rounded, rarely retuse or bidentate; underleaves none (in our species). Monœcious or diœcious. Involucral leaves 2–4 pairs, connate at base. Perianth subcompressed laterally, connate with the involucral leaves. Antheridia terminal on somewhat spike-like stems. (Named for S. Nardi, an Italian abbot.)

§ 1. EÙCALYX. Perianth connate at base with the inner involucral leaves, somewhat surpassing them, 3–8-carinate, the mouth constricted.

1. N. hyalìna, Carring. Creeping, with ascending tips, the branches dichotomous-fastigiate, with claret-colored rootlets; leaves loosely imbricate, decurrent, roundish, repand-undulate; monœcious or diœcious; involucral leaves broader, appressed, one connate with the lower third of the perianth, which is somewhat exserted, obovate, plicate with acute rough angles, rostellate, at length 4-cleft; capsule round-ovate. (Jungermannia hyalina, Lyell.)—On banks in woods, Closter, N. J. (Austin), Ohio (Lesquereux). (Eu.)

2. N. crenulàta, Lindb. (Pl. 25.) Prostrate, branching; leaves orbicular, entire, larger toward the involucre and with large marginal cells; diœcious; involucral leaves 2, rarely 3, adnate to the base of the perianth, which is flattened or terete, more or less regularly 4–5-plicate, the angles smooth; mouth much contracted, toothed. (Jungermannia crenulata, Smith.)—On the ground in old fields, N. Y. and southward. (Eu.)

3. N. crenulifórmis, Lindb. Densely cespitose; fertile stems creeping, thickened upward, with numerous purple rootlets, the sterile subascending, attenuate upward; leaves subdecurrent, obliquely spreading, orbicular, concave, entire or nearly so; perianth small, subobovate, more or less connate with the involucral leaves, not exserted or slightly so, rooting at base, triquetrous above, becoming 4–7-plicate; calyptra often violet-purple; capsule oval-globose. (Jungermannia crenuliformis, Aust.)—On rocks in rivulets, Closter, N. J. (Austin), Coshocton Co., Ohio (Sullivant).

4. N. bifórmis, Lindb. Densely cespitose, much branched, innovating from beneath; rootlets numerous; leaves scarcely imbricate, alternate, spreading, obliquely semicircular or broadly ovate, retuse or entire, decurrent dorsally; cells large, hyaline; branch-leaves half as large, ovate or obovate, scarcely decurrent; diœcious; antheridia solitary; fruit unknown. (Jungermannia biformis, Aust.)—On steep wet rocks, Delaware Water Gap, N. J. (Austin).

§ 2. CHASCÓSTOMA. Perianth exserted, subcampanulate and open, deeply laciniate, connate with the involucral leaves.

5. N. fossombronioìdes, Lindb. Stems densely cespitose, ascending; rootlets numerous, purple; leaves 2-ranked, subvertical, spreading-subrecurved, rooting, closely imbricate, orbicular, clasping by a slightly cordate base, subventricose, undulate-repand, the apex uniplicate and slightly emarginate; monœcious; perianth very large, 6–10-plicate, the lobes entire; calyptra violet; capsule short-oval. (Jungermannia fossombronioides, Aust.)—On rocks in a rivulet, Closter, N. J. (Austin), and southward.

27. GYMNOMÍTRIUM, Corda. (Pl. 23.)

Leaves closely imbricated, 2-ranked on fascicled ascending julaceous stems, emarginate-bidentate; underleaves none. Diœcious. Involucre double, the inner shorter, of 2 or more dentate and deeply cleft leaves. Calyptra short, campanulate. Capsule globose, the valves at length reflexed. Elaters caducous. Antheridia in the axils of leaves, oval, stipitate. (Name from γυμνός, naked, and μιτρίον, a little cap.)

1. G. concinnàtum, Corda. Stems simple or imbricately branching, thickened at the apex; leaves ovate, bifid, with a narrow scarious margin. (Cesia concinnata, S. F. Gray.)—Alpine regions of the White Mts. (Oakes).—Grayish or silvery-olive. (Eu.)

28. FOSSOMBRÒNIA, Raddi. (Pl. 23.)

Stems thalloid, with large subquadrate succubous leaves; underleaves none. Diœcious or monœcious. Fruit terminal or by innovation dorsal on the main stem. Involucral leaves 5–6 (in our species), small, subulate, adnate. Perianth open-campanulate or obpyramidal, crenate-lobed. Calyptra free, sub-globose. Capsule short-pedicelled, globose, irregularly valved. Elaters very short, 1–3- (mostly 2-) spiral, free. Spores large, very rough. Antheridia 2–3, short-pedicelled, naked. Perfect archegonia 2–3. (Named for V. Fossombroni, an Italian Minister of State.)

[*] Plant large or of medium size; stems mostly simple.

1. F. pusílla, Dumort. (Pl. 23.) Stems 6–10´´ long; leaves retuse, entire or irregularly indented; perianth obconic, dentate; elaters short and thick; spores brown, depressed-globose-tetrahedral, 40 µ broad, crested, the slender crests pellucid, rarely becoming confluent.—On damp ground. Its occurrence in America is doubtful. (Eu.)

2. F. Dumortièri, Lindb. Cespitose, greenish or brownish-yellow; stems 3–6´´ long, 1´´ wide, shortly bifurcate; rootlets copious, purple; leaves numerous, smaller toward each end of the stem; monœcious; perianth large, broadly obpyramidal; calyptra nearly as long; elaters scanty; spores globose-tetrahedral yellowish-brown, regularly pitted.—White Mts. (Farlow), N. J. (Austin), and perhaps elsewhere; confused with n. 1.

3. F. angulòsa, Raddi. Stems narrowly forked at the apex; leaves horizontal, subquadrate, the upper undulate-lobed; diœcious; perianth dilated-conic, crenate; spores brownish-yellow, globose-tetrahedral, not depressed, 30 µ broad, deeply reticulated, the reticulations large, 5–6-angled.—Brackish meadows, common; fruiting in early spring. (Eu.)

[*][*] Plant minute; stems forked or fastigiately divided.

4. F. crístula, Aust. Stems 1–2´´ long; leaves whitish, quadrate or round-obovate, subentire, strongly crisped-undulate; capsule immersed on a short pedicel; elaters short, more or less diverse, with a single narrow annular and spiral fibre; spores pale fuscous, more or less tuberculate.—On moist sand in unfrequented paths, Batsto, N. J. (Austin).

29. PALLAVICÍNIA, S. F. Gray. (Pl. 22.)

Thallus with a distinct costa. Fruit arising from the costa, at first terminal, becoming dorsal. Diœcious. Involucre cup-shaped, short-lacerate. Perianth long-tubular, denticulate. Calyptra irregularly lacerate. Capsule slender-cylindric. Elaters slender, free. Spores minute. Antheridia dorsal, covered with minute fimbriate scales. (Named for L. Pallavicini, Archbishop of Genoa.)

1. P. Lyéllii, S. F. Gray. Thallus thin, 1–4´ long, 3–5´´ wide, simple or bifid, the margin entire, slightly crenate or serrate; cells large, oblong-hexagonal; perianth erect, fleshy (5 cells thick below), the somewhat constricted mouth lobate-ciliolate; pedicel long, exceeding the thallus; capsule cylindric, five times as long as broad. (Steetzia Lyellii, Lehm.)—Among mosses in swamps and on dripping rocks; common, especially southward. (Eu.)

30. BLÀSIA, Micheli. (Pl. 23.)

Thallus simple or forked or stellate, with sinuous margins. Diœcious. Fruit from an oval cavity in the costa. Involucre mostly none. Calyptra obovate. Capsule oval-globose. Antheridia immersed in the thallus, covered with dentate scales. Gemmæ globose, issuing by a slender ascending tube from large flask-shaped receptacles which are immersed in the thallus. (Named for Blasius Biagi, a monk of Valombrosa and companion of Micheli.)

1. B. pusílla, L. Thallus ¾–1½´ long, 2–3´´ wide, narrowly obovate, the margins pinnatifid-sinuous.—Wet banks; common. (Eu.)

31. PÉLLIA, Raddi. (Pl. 23.)

Thallus with a broad indeterminate costa. Monœcious or diœcious. Fructification dorsal near the end of the thallus. Involucre short, cup-shaped, lacerate-dentate. Calyptra membranous, oval, longer or shorter than the involucre. Capsule globose. Elaters long, free. Antheridia globose, immersed in the costa. (Named for A. L. Pelli, an Italian botanist.)

[*] Monœcious.

1. P. epiphýlla, Raddi. (Pl. 23.) Thallus oblong, lobed and sinuate, somewhat fleshy, much thickened in the middle; capsule exserted.—On the ground in wet places; not uncommon eastward. (Eu.)

[*][*] Diœcious.

2. P. endiviæfòlia, Dumort. Thallus flat, green or purplish, broadly linear, dichotomous, the margin mostly undulate or crisped.—On the ground and in ditches; common, but often confused with n. 1. (Eu.)

3. P. calycìna, Nees. Thallus dichotomous, proliferous, the early divisions linear-oblong, the margins ascending and remotely sinuate, the later divisions linear-palmatifid, coarsely nerved; cells large, hexagonal; involucre ciliate-fringed or lacerate; calyptra smooth, included.—Wet limestones and shales. (Eu.)

32. METZGÈRIA, Raddi. (Pl. 23.)

Thallus linear, dichotomous, with well defined costa. Diœcious. Fructification arising from the under side of the costa. Involucre 1-leaved, scale-like, at length ventricose. Calyptra clavate or pyriform, fleshy. Capsule short-pedicelled. Elaters unispiral, some remaining attached to the tips of the valves. Spores minute, mostly smooth. Antheridia globose, enclosed in a scale on the under surface of the costa. (Named for J. Metzger, a German botanist.)

[*] Densely villous throughout.

1. M. pubéscens, Raddi. Thallus 1–2´ long, 1´´ wide, alternately pinnate or somewhat decompound, the short linear branches of uniform width, flat, the margin undulate; hairs longer beneath, single or in twos and threes near the margin, irregularly curved; midrib nearly without cortical layer, with 6–10 (mostly 8) rows of very uniform peripheral cells; diœcious.—In mountain regions, eastward. (Eu.)

[*][*] Hairy on the margins and midrib beneath, smooth above; diœcious (n. 4 monœcious).

2. M. myriópoda, Lindb. Thallus elongated (2´ long, ½´´ wide), dichotomous, the long linear branches of uniform width, convex above, the reflexed margins not undulate; midrib densely pilose beneath; hairs rather long, straight or nodding, the marginal mostly in clusters of 3–6, some with discoid tips; midrib covered above with 2 rows of enlarged cells, and beneath with 3–7 (usually 4–6) rows of smaller cells, lax and often indistinct. (M. furcata, Sulliv., in part; not Nees.)—Shaded rocks and trees in the Alleghanies (Sullivant), and southward.

3. M. hamàta, Lindb. Like the last; thallus much elongated (4´ long, 1–1½´´ wide); hairs very long, divaricate and hooked-deflexed, the marginal in twos, rarely with discoid tips; midrib covered above and below with two rows of enlarged lax cells. (M. furcata, Sulliv., in part.)—Alleghany Mts. (Sullivant).

4. M. conjugàta, Lindb. Thallus 1½´ long, ½–1´´ wide, usually dichotomous, the short branches irregular in width, convex above, the margins more or less undulate; hairs rather long, straight, divaricate, the marginal usually in twos, very often disk-bearing; midribs covered above with 2, below with 3–6 rows of enlarged lax cells.—On shaded rocks and trunks of trees, central N. Y., and southward. (Eu.)

33. ANEÙRA, Dumort. (Pl. 23.)

Thallus fleshy, prostrate or assurgent from a creeping base; costa obscure. Diœcious or monœcious. Fructification arising from the under side near the margin. Involucre cup-shaped, short and lacerate, or none. Calyptra large, fleshy, more or less clavate. Capsule large, oblong-cylindric. Elaters unispiral, in part adherent to the tips of the valves. Spores minute, smooth or minutely roughened. Antheridia immersed in the surface of receptacles proceeding from the margin of the thallus. (Name from α- privative, and νεῦρον, a nerve.)

[*] Thallus narrow (about 1´´ wide), palmately divided.

1. A. látifrons, Lindb. Thallus cespitose, ascending or erect, usually dark green, 6–9´´ long, mostly pellucid; branches linear, obtuse and emarginate, plano-convex; cells large, oblong-rhombic; monœcious; archegonia 3–10, short, conic; calyptra white, verrucose, pyriform-clavate; capsule oval, brown; spores 12½–14½ µ broad, globose, minutely and densely papillose; antheridia globose. (A. palmata of authors; not Dumort.)—On rotten logs; common.

[*][*] Thallus narrow (about 1´´ wide), pinnate or bipinnate.

2. A. multífida, Dumort. Thallus prostrate, brownish-green, pinnately divided, the primary portion biconvex, somewhat rigid, the branches horizontal, pectinately pinnate with narrow linear divisions; monœcious; fructification rising from the primary part or from the branches; involucre fleshy; calyptra tuberculate.—Var. màjor, Nees. Primary portion and branches thick, the branches interruptedly pinnate with short obtuse divisions.—On decayed wood and moss in swamps, N. J. (Austin), and south in the mountains. (Eu.)

3. A. pinnatífida, Nees. Thallus pinnately divided or subsimple, flat or somewhat channelled; branches horizontal, the broader pinnatifid or dentate, obtuse; calyptra somewhat smooth.—On dripping rocks, Hokokus, N. J. (Austin), N. Haven, Conn. (Eaton). (Eu.)

[*][*][*] Thallus wider (2´´ or more), simple or irregularly lobed.

4. A. séssilis, Spreng. Thallus decumbent, irregularly lobed, 1–2´ long, 3–5´´ wide; involucre none; pedicel ¾–1´ long, sometimes folded upon itself and remaining within the calyptra, the capsule thus appearing sessile; antheridia on elongated receptacles.—Wooded swamps. Elongated floating forms, 5–6´ long, have been found in the White Mts. (Farlow, Faxon).

5. A. pínguis, Dumort. Thallus 1–2´ long, decumbent or ascending, fleshy, linear-oblong, simple or slightly lobed, the margin sinuate; diœcious; involucre short, lacerate; calyptra cylindric, smooth; capsule brownish, furrowed; antheridia in 2-lobed receptacles.—Wet banks, N. J. to Ohio, and southward. (Eu.)

Order 138. ANTHOCEROTÀCEÆ. (Horned Liverworts.)

Plant-body a thallus, irregularly branching, flaccid, without epidermis or pores, and more or less vesiculose. Involucre single, tubular. Calyptra rupturing early near the base, and borne on the apex of the capsule. Capsule dorsal, pod-like, erect or curved outward, more or less perfectly 2-valved, usually stomatose, tapering into a pedicel or often sessile with a bulbous base. Columella filiform. Elaters with or without spiral fibres. Spores flattish, more or less convex-prismatic, papillose or smooth.

1. Anthoceros. Capsule narrowly linear, exsertly pedicelled, 2-valved. Elaters present.

2. Notothylas. Capsule very short, sessile, not valved below the middle. Elaters not obvious.

1. ANTHÓCEROS, Micheli. (Pl. 22.)

Thallus dark green or blackish, usually depressed, variously lobed, with large chlorophyll-grains, frequently glandular-thickened at the apex or in lines along the middle so as to appear nerved. Monœcious or diœcious. Capsule linear, 2-valved, exsertly pedicelled. Elaters simple or branched, often geniculate, more or less heteromorphous, the fibres wanting or indistinct. (Name from ἄνθος, flower, and κέρας, horn, from the shape of the capsule.)

1. A. læ̀vis, L. (Pl. 22.) Thallus smooth, nearly flat above; diœcious; involucre 1–2´´ long, trumpet-shaped when dry, repand-toothed; capsule pale brown or yellowish, 1–1½´ long; elaters rather short, yellowish; spores yellow, nearly smooth, angular.—Wet clay banks, from Canada south and westward. (Eu.)

2. A. punctàtus, L. Thallus small, depressed, or often cespitose and erect, more or less glandular; monœcious; involucre rather short, oblong-linear, slightly repand, sometimes scarious at the mouth; capsule 1´ high, black; elaters fuscous, flattish, geniculate; spores black, strongly muriculate, sharply angled.—Wet banks, Canada to Mo., and southward. (Eu.)

2. NOTOTHỲLAS, Sulliv. (Pl. 22.)

Thallus orbicular, tender, laciniate and undulate or crisped, papillose-reticulate. Monœcious. Involucre sessile, continuous with the thallus, opening irregularly above. Capsule very short, oblong-globose or ovate-cylindric, pedicelled from a thickened bulb, 2-valved to the middle or rupturing irregularly. Elaters none, or fragmentary and inconspicuous. Spores subglobose, smoothish. Antheridia elliptic-globose, immersed in the thallus. (Name from νῶτος, the back, and θυλάς, a bag, from the shape and position of the involucre.)

1. N. orbiculàris, Sulliv. (Pl. 22.) Thallus 3–8´´ wide; capsules 1–2´´ long, erect or decurved, wholly included or slightly exserted, of thin and loose texture, with a suture on each side; spores light yellowish-brown. (Including N. valvata, Sulliv.)—Wet places, Canada to the Gulf.

2. N. melanóspora, Sulliv. Thallus small, depressed or sometimes cespitose, of lax texture; capsule often without sutures; spores dark brown, a half larger.—Moist ground, Ohio (Sullivant).

Order 139. MARCHANTIÀCEÆ. Liverworts.

Plant-body a thallus, dichotomous or subpalmately branching, usually innovating from the apex or beneath it, more or less thickened in the middle, and bearing numerous rootlets beneath and usually colored or imbricating scales. Epidermis usually more or less distinct and strongly porose above. Capsules globose, rarely oval, opening irregularly, pendent from the under side of a peduncled disk-like receptacle (carpocephalum). Elaters present, mostly 2-spiral.

[*] Thallus plainly costate, distinctly porose except in n. 6.

[+] Gemmæ present on sterile stems.

1. Marchantia. Gemmæ in cup-shaped receptacles. Fertile receptacle 7–11-rayed.

8. Lunularia. Gemmæ in crescent-shaped receptacles. Fertile receptacle cruciform.

[+][+] Gemmæ wanting.

[++] Receptacle conic-hemispherical, 2–4-lobed; perianth lobed or fringed.

2. Preissia. Receptacle 2–4-lobed, with as many alternate rib-like rays. Perianth 4–5-lobed.

3. Fimbriaria. Receptacle 4-lobed. Perianth conspicuous, split into 8–16 fringe-like segments.

[++][++] Receptacle more or less conical; perianth none.

4. Conocephalus. Thallus very large, strongly areolate. Receptacle conical, membranous.

5. Grimaldia. Thallus small. Peduncle chaffy at base and apex. Receptacle conic-hemispheric, truncately 3–4-lobed.

6. Asterella. Thallus eporose. Receptacle conic-hemispheric, becoming flattened, acutely 4- (1–6-) lobed.

[*][*] Thallus thin, ecostate or barely costate.

7. Dumortiera. Receptacle convex, 2–8-lobed. Perianth none.

1. MARCHÁNTIA, Marchant f. (Pl. 22.)

Thallus large, forking, areolate, porose, with broad diffused midrib; gemmæ in a cup-shaped receptacle. Diœcious. Fertile receptacle peduncled from an apical sinus of the thallus, radiately lobed. Involucres alternate with the rays, membranous, lacerate, enclosing 3–6 1-fruited cleft perianths. Calyptra persistent. Capsule globose, exserted, pendulous, dehiscing by several revolute segments. Elaters long, attenuate to each end. Spores smooth. Antheridia immersed in a peduncled disk-like radiate or lobed receptacle. (Named for Nicholas Marchant, a French botanist.)

1. M. polymórpha, L. Thallus 2–5´ long, ½–1½´ wide, numerously porose, venulose; receptacle divided into usually 9 terete rays; peduncles 1–3´ high; antheridial disk crenately or palmately 2–8-lobed, on a peduncle 1´ high or less.—Everywhere common. (Eu.)

2. PREÌSSIA, Nees. (Pl. 22.)

Thallus obcordate, sparingly forked, increasing by joints; pores conspicuous; gemmæ none. Diœcious or monœcious. Fertile receptacle hemispheric, 1–4-lobed, with as many alternating shorter rib-like rays. Outer involucres attached beneath the lobes, 1–3-fruited, opening outward by an irregular line; perianth obconic-campanulate, angular, unequally 4–5-lobed. Calyptra persistent. Capsule large, distinctly pedicelled, dehiscing by 4–8 revolute segments. Elaters short. Spores coarsely tuberculate. (Named for L. Preiss, a German botanist.)

1. P. commutàta, Nees. Thallus 1–2´ long, with conspicuous white pores above, and dark purple scales beneath; usually monœcious; peduncle ½–1´ high; capsules conspicuous, dark purple; antheridia in a peduncled disk-like receptacle. (P. hemisphærica, Cogn.)—On slaty and limestone rocks, from N. J. north and westward. (Eu.)

3. FIMBRIÀRIA, Nees. (Pl. 22.)

Thallus thickened in the middle by a keeled costa, usually conspicuously porose, with dark purple scales beneath; gemmæ none. Monœcious. Receptacle rising from the apex, conic or hemispheric, concave beneath and expanded into usually 4 large campanulate 1-fruited involucres. Perianth oblong-oval or subconic, exserted half its length and cleft into 8–16 fringe-like segments. Calyptra with a long style, fugacious. Capsule nearly sessile, irregularly circumscissile. Elaters rather short, 1–4-spiral. Spores angular, subreticulated. Antheridia immersed in the thallus. (Name from fimbria, a fringe, alluding to the perianth.)

1. F. tenélla, Nees. Thallus of one or more long-wedge-shaped emarginate divisions about 6–9´´ long, grayish-green and porose above, purple on the margins; peduncle 1´ high or more, usually purple; receptacle obtusely conic; perianth white, 8-cleft.—On damp ground in sandy fields or on rocks, central N. Y. to Mo., and southward.

4. CONOCÉPHALUS, Neck. (Pl. 22.)

Thallus dichotomous, copiously reticulate and porose, with a narrow costa; gemmæ none. Receptacle conic-mitriform, membranous. Involucres 5–8, tubular, 1-fruited, suspended from the apex of the peduncle; perianth none. Calyptra persistent, campanulate, 2–4-lobed at the apex. Capsule pedicelled, oblong-pyriform, dehiscing by 5–8 revolute segments. Elaters short, thick. Spores muriculate. Antheridia imbedded in an oval disk sessile near the apex of the thallus. (Name from κῶνος, a cone, and κεφαλή, a head.)

1. C. cónicus, Dumort. Thallus 2–6´ long, ½–¾´ wide; receptacle conic, striate, crenate. (Fegatella conica, Corda.)—Shady banks; common. (Eu.)

5. GRIMÁLDIA, Raddi. (Pl. 23.)

Thallus thick, more or less channelled, dichotomous, innovating from the apex, with thick epidermis, closely areolate and porose-scabrous above, purple and more or less scaly beneath; gemmæ none. Monœcious or diœcious. Receptacle peduncled, hemispherical or conoidal, 3–4-lobed. Involucres as many, 1-fruited, each a distention of the lobe. Capsule filling the involucre, circumscissile in the middle, the calyptra persistent at its base. Antheridia in an oval or obcordate disk immersed in the apex of the thallus. (Named for D. Grimaldi, an Italian botanist.)

1. G. bárbifrons, Bisch. (Pl. 23.) Thallus linear-obcuneate, 3–6´´ long, 1–2´´ wide, 2-lobed at the apex, pale green with usually distinct whitish pores, the scales beneath often extending far beyond the margin and becoming whitish; peduncle profusely chaffy at base and apex, sometimes much reduced; antheridial disks obcordate. (Including G. sessilis, Sulliv.)—Thin soil on rocks, Conn. and N. J. to Iowa; rare or local. (Eu.)

2. G. rupéstris, Lindenb. Thallus 3–6´´ long, 1–3´´ wide, with membranous margins; receptacle small, hemispherical, 1–4-fruited, the peduncle about 1´ high, sparingly scaly at base, barbulate at the apex; involucre short, crenulate; spores tuberculate. (Duvalia rupestris, Nees.)—On calcareous or shaly rocks, N. Y. and Ohio. (Eu.)

6. ASTERÉLLA, Beauv. (Pl. 22.)

Thallus rigid, very indistinctly porose, the midrib broad, strong and distinct. Receptacle conic-hemispheric, becoming flattened, 1–6- (usually 4-) lobed. Monœcious. Involucres coherent with the lobes, 1-fruited, 2-valved. Calyptra minute, lacerate, persistent at the base of the capsule. Capsule greenish, rupturing by irregular narrow teeth or by a fragmentary operculum. Elaters moderately long, mostly 2-spiral. Spores tuberculate. Antheridia in sessile lunate disks. (Diminutive of aster, a star, from the form of the receptacle.)

1. A. hemisphæ̀rica, Beauv. Thallus forking and increasing by joints, pale green, purple beneath; receptacle papillose on the summit (less so at maturity); peduncle bearded at base and apex, ¾–1´ long, often 2–3 times longer after maturity. (Reboulia hemisphærica, Raddi.)—Shaded banks, chiefly along streams; more common southward.—A smaller form or perhaps variety (Reboulia microcephala, Nees; R. Sullivantii, Lehm.) occurs in Penn., Ohio, and southward. (Eu.)

7. DUMORTIÈRA, Nees. (Pl. 22.)

Thallus large, thin, soft, with a slight costa, dichotomous, usually with scattered hair-like rootlets beneath; gemmæ none. Receptacle convex, 2–8-lobed. Involucres 1-fruited, connate with the lobes beneath, horizontal, opening by a vertical terminal slit. Capsule distinctly pedicelled, oblong-globose, dehiscing by 4–6 irregular valves. Elaters 2–3-spiral, parietal, very long, straight, attenuate both ways. Spores muriculate. Antheridia in a short peduncled disk paleaceous beneath. (Named for B. C. Dumortier, a Belgian botanist.)

1. D. hirsùta, Nees. Thallus 2–5´ long, 6–9´´ wide, deep green, becoming blackish, entire on the margins, naked above or with a delicate appressed pubescence; diœcious; receptacle many-fruited, the margin closely hairy; peduncle rather long, chaffy at the apex.—On moist calcareous rocks, Easton, Penn. (Porter), and southward.

8. LUNULÀRIA, Micheli. (Pl. 25.)

Thallus oblong with rounded lobes, distinctly areolate and porose, with imbricate sublunate scales beneath; gemmæ in crescent-shaped receptacles. Diœcious. Fertile receptacle usually cruciately divided into 4 horizontal segments or involucres, which are tubular, vertically bilabiate and 1-fruited. Calyptra included, persistent. Capsule exserted, 4–8-valved. Elaters short, very slender, mostly free. Spores nearly smooth. Antheridia borne in the apical sinus of the thallus. (Name from lunula, a little moon.)

L. vulgàris, Raddi. Thallus 1–2´ long, forked, innovating from the apex, with a somewhat diffuse costa; peduncle very hairy, 1–1½´ long.—Introduced into greenhouses; always sterile, but easily recognized by the characteristic receptacles. (L. cruciata, Dumort.) (Int. from Eu.)

Order 140. RICCIÀCEÆ.

Plant-body a dichotomously branching thallus, terrestrial or aquatic. Capsules short-pedicelled, or sessile on the thallus, or immersed in its substance, free or connate with the calyptra, globose, at length rupturing irregularly. Calyptra crowned with a more or less deciduous point. Elaters none. Spores usually angular, reticulate or muriculate. Antheridia ovate, immersed in the thallus in flask-shaped cavities with protruding orifices (ostioles).

1. Riccia. Capsule immersed in the thallus. Involucre none.

2. Sphærocarpus. Capsule sessile on the thallus. Involucre inflated-pyriform.

1. RÍCCIA, Micheli. (Pl. 22.)

Thallus at first radiately divided, the centre often soon decaying; the divisions bifid or di–tri-chotomous, flat or depressed or channelled above, usually convex and naked or squamulose beneath; margins naked or spinulose-ciliate; epidermis usually distinct, eporose; air-cavities evident or wanting. Capsule immersed, sessile. Calyptra with a persistent style. Spores alveolate or muriculate, usually flattened and angular. (Named for P. F. Ricci, an Italian nobleman, patron of Micheli.)

§ 1. LICHENÒDES. Fruit mostly protuberant above; spores about 84 µ broad, issuing through openings in the upper surface of the thallus; terrestrial species (on damp, usually trodden or cultivated ground), without air-cavities.

[*] Thallus naked, without cilia or scales.

1. R. Fróstii, Aust. Thallus orbicular, 6–12´´ broad, thinnish, grayish-green, the apex and narrowly membranous margins sometimes purplish, minutely pitted; divisions linear or subspatulate, subtruncate and slightly emarginate; rootlets smooth or obsoletely papillose within; capsules very prominent beneath; spores barely 50 µ broad, nearly round, somewhat margined, with depressed sides when dry, fuscous.—Ohio, Ill., and westward.

[*][*] Thallus with white scales beneath (dark purple in n. 4), the margin naked.

2. R. sorocárpa, Bisch. Thallus 3–8´´ in diameter, pale green becoming whitish, finely reticulate, subradiately or dichotomously divided, the oblong-linear segments subacute, deeply sulcate, with a few inconspicuous scales toward the apex not extending beyond the margin; margins erect when dry; spores issuing through chinks early appearing along the groove above.—Thin rocky soil and cultivated fields, Closter, N. J. (Austin), western N. Y. (Clinton), and Ill. (Hall). (Eu.)

3. R. lamellòsa, Raddi. Thallus pale green, elegantly reticulated, subradiately divided, the divisions obovate or obcordate, bifid or 2-lobed, 2–5´´ long, channelled at the apex, with membranous ascending margins, and furnished beneath with transverse scales which extend considerably beyond the margin; spores much as in n. 2.—Thin rocky soil, Closter, N. J. (Austin).

4. R. nigrélla, DC. Thallus dichotomously divided, the divisions linear, channelled, with entire narrowly membranous margins, green above, dark purple beneath and furnished with transverse semicircular scales not exceeding the margin.—Rocky ground, N. Y. (Torrey), and Chester, Penn. (Porter). (Eu.)

[*][*][*] Thallus more or less ciliate, naked beneath or obsoletely squamous along the extreme edge.

5. R. arvénsis, Aust. Thallus much divided, 3–9´´ broad, papillose-reticulate, dull green both sides, becoming fuscous above, the flat margins at length purple; divisions sulcate, dichotomous, the linear-elliptic or subspatulate lobes acutish and obsoletely emarginate; cilia whitish, very short and inconspicuous or nearly wanting; capsules aggregated toward the apex; spores 71–84 µ broad, dark fuscous, reticulate, with pellucid margin.—Var. hírta, Aust., decidedly ciliate and with spine-like hairs scattered over the upper surface; divisions broader, more obtuse; spores nearly black, larger (84–101 µ) and smoother.—Cultivated fields and (the var.) rocky places, Closter, N. J. (Austin).

6. R. Lescuriàna, Aust. Stellately or subcruciately divided, the obcordate or cuneate-linear divisions 2–6´´ long, punctate-reticulate, subglaucous or ashy-green both sides or becoming purple beneath, the slightly concave lobes emarginate, closely ciliate with short obtuse spine-like white hairs; capsules scattered, chiefly near the base of the divisions; spores 71–83 µ broad, dark brown, reticulate, not margined.—Cultivated fields and rocky grounds, N. J. to Ill., and southward.

§ 2. SPONGÒDES. Thallus with large air-cavities usually opening by pits through the upper surface, and with slight depressions over the capsules which are prominent beneath; spores 41–51 µ broad, obtusely angular or globose; terrestrial.

7. R. crystállina, L. Orbicular, 6–9´´ broad, the obcordate or cuneate divisions bifid or 2-lobed, flat above and the surface much broken up into pits, the margins subcrenate; capsules scattered; spores issuing through the upper surface.—On mud flats, Ill. (Hall), west and southward. (Eu.)

8. R. lutéscens, Schwein. Orbicular, 1–1½´ in diameter, light green; divisions 6–8, linear, 2–3 times forked, narrowly channelled, obcordate and thickened at the apex, with delicate whitish obliquely ovate appressed scales, rootlets wanting beneath above the middle; fruiting plant unknown.—Dried up pools and ditches, Canada to Mo., and southward. An analogous form has been developed by Lindberg from R. natans.

9. R. ténuis, Aust. Thallus thin, olive or yellowish-green, shining, the 2–4 divisions roundish-obovate, 2–4´´ long, flat, with sinuate margins, green beneath with a slender costa and few rootlets; capsule very delicate, closely adherent to the substance of the thallus, minutely apiculate; spores round or short-oval, conspicuously depressed at one end when dry.—Wet ground in open woods, Closter and Lawrence, N. J. (Austin), and Mo. (Hall).

§ 3. RICCIÉLLA. Thallus linear, dichotomous, floating or rarely terrestrial; capsule protuberant from the lower surface.

10. R. flùitans, L. Thallus often in extended patches, thin, green, radiately expanding, the often imbricate divisions ½–1½´´ wide, parallel-nerved, flat, without rootlets, cavernous only toward the slightly dilated very obtuse or subtruncate apex; capsules present only in some terrestrial forms, very prominent below, rupturing beneath the apex.—Very variable. The most notable form is var. Sullivánti, Aust., with divisions about ½´´ wide, channelled, cavernous throughout, the margins crisped-crenulate, and rootlets numerous on the costa tumid with abundant capsules, which are tipped with a long funnel-mouthed point; spores obscurely angled, reticulate and margined. (R. Sullivanti, Aust.)—In ponds or ditches or growing in wet places upon the ground; the variety often in cultivated fields. (Eu.)

§ 4. RICCIOCÁRPUS. Thallus obcordate, floating or rarely terrestrial; capsules not protruding, at length exposed by a cleft in the central groove.

11. R. nàtans, L. (Pl. 22.) Divisions obcordate or cuneate, broadly emarginate, 3–6´´ long, purplish, very narrowly channelled, with numerous uniform air-cavities beneath the epidermis, rooting toward the base and at length with dark purple scales beneath the apex; capsules in 1 or 2 rows beneath the groove; spores black, angular, strongly papillose.—Canada to the Gulf. (Eu.)

2. SPHÆROCÁRPUS, Micheli. (Pl. 22.)

Thallus lobed, without costa or epidermis. Involucres sessile, obconic or pyriform, perforated at the apex, continuous with the thallus at base. Calyptra closely investing the single globose indehiscent capsule, crowned with a deciduous point. Spores globose, muriculate, remaining united in a coccus. Antheridia borne in follicular bodies on the surface of a separate thallus.—An anomalous genus, perhaps more closely related to the Jungermanniaceæ. (Name from σφαῖρος, a sphere, and καρπός, fruit.)

1. S. terréstris, Smith. Thallus orbicular, 3–6´´ broad, covered by the clustered inflated involucres, which are nearly 1´´ long, 3–4 times the length of the capsule; coccus 102–127 µ wide, indistinctly lobed. (S. Michelii, Bellardi.)—In cultivated fields, mostly southern. (Eu.)