THE PLANTS OF MICHIGAN (continued 2)

18b. Leaves firm or thick, shining above; fruit reddish, small, consisting of a few sour drupelets Swamp Dewberry, Rubus hispidus.

19a. Ripe fruit dropping away from the white receptacle or core; terminal leaflet of each leaf with a long stalk, while the lateral leaflets are sessile or nearly so (Raspberry) — 20.

19b. Ripe fruit and receptacle or core dropping together; all the leaflets on stalks which are approximately equal in length (Blackberry) — 22.

20a. Stem very glaucous with a whitish or bluish waxy deposit; fruit black Black Raspberry, Rubus occidentalis.

20b. Stem not glaucous; fruit red — 21.

21a. Calyx velvety-pubescent Red Raspberry, Rubus idaeus.

21b. Calyx bristly-hispid Red Raspberry, Rubus idaeus var. aculeatissimus.

22a. Pedicels with gland-tipped hairs, but no prickles Blackberry, Rubus allegheniensis.

22b. Pedicels with prickles Blackberry, Rubus nigricans.

22c. Pedicels with neither prickles nor gland-tipped hairs — 23.

23a. Leaves downy beneath Blackberry, Rubus frondosus.

23b. Leaves smooth beneath Blackberry, Rubus canadensis.

24a. Ovaries 1 or more, superior (attached to the surface of the receptacle, but not concealed within it or united to it) — 25.

24b. Ovary 1, inferior (permanently enclosed within the receptacle, with only the styles protruding) — 38.

25a. Ovaries more than 1 — 26.

25b. Ovary 1 — 30.

26a. Leaves serrate — 27.

26b. Leaves lobed — 28.

27a. Leaves glabrous or very nearly so (8-20 dm. high; flowers white or pinkish, summer) Meadow-sweet, Spiraea salicifolia.

27b. Leaves closely pubescent beneath (5-15 dm. high; flowers pink, summer) Hardhack, Spiraea tomentosa.

28a. Flowers showy, purple or white, 3-4 cm. broad — 29.

28b. Flowers white, about 1 cm. wide (1-3 m. high; flowers in early summer) Ninebark, Physocarpus opulifolius.

29a. Flowers purple Flowering Raspberry, Rubus odoratus.

29b. Flowers white Salmonberry, Rubus parviflorus.

30a. Flowers in racemes (trees or tall shrubs; flowers white, in late spring) — 31.

30b. Flowers in small umbels or corymbs (flowers white, in spring) — 32.

31a. Leaves oblong, the points of their teeth incurved Black Cherry, Prunus serotina.

31b. Leaves obovate, the points of their teeth spreading Choke Cherry, Prunus virginiana.

32a. Flowers about 1 cm. wide — 33.

32b. Flowers about 1.5-2.5 cm. wide — 36.

33a. Low shrubs, with the spatulate or oblong leaves widest above the middle — 34.

33b. Erect tall shrubs or small trees, with the leaves widest below the middle — 35.

34a. An erect shrub (5-10 dm. high) Appalachian Cherry, Prunus cuneata.

34b. A prostrate or ascending shrub (3-15 dm. high) Sand Cherry, Prunus pumila.

35a. Leaves very broadly ovate, almost as wide as long (small tree) Perfumed Cherry, Prunus mahaleb.

35b. Leaves oblong-lanceolate, about 3 times as long as broad (shrub or small tree, 2-10 m. high) Pin Cherry, Prunus pennsylvanica.

36a. Sepals glandular-serrate (tall shrub or small tree) Wild Plum, Prunus nigra.

36b. Sepals entire — 37.

37a. Leaves with sharp teeth, frequently bristle-tipped; a native species (tall shrub or small tree, frequently growing in thickets) Wild Plum, Prunus americana.

37b. Leaves with obtuse teeth; a species escaped from cultivation (widely branched tree) Cherry, Prunus cerasus.

38a. Trees, in cultivation or escaped from cultivation near roads or dwellings, with showy flowers 2.5-5 cm. across, edible fruits, and no thorns (spring) — 39.

38b. Native species, trees or shrubs, growing in woods, fields, or thickets; frequently with thorns (spring) — 40.

39a. Leaves finely serrulate or entire Pear, Pyrus communis.

39b. Leaves coarsely serrate or somewhat lobed Apple, Pyrus malus.

40a. Shrubs or small trees, without thorns — 42.

40b. Bushy trees or shrubs, with thorns or stiff thorn-like branches, and with flowers generally 1.5-2.5 cm. across — 41.

41a. Flowers pink, very fragrant Wild Crab, Pyrus coronaria.

41b. Flowers white (Hawthorn, the genus Crataegus). Several species of this genus occur in the state, for the identification of which the Manual must be used.

42a. Mid-vein glandular above (shrubs 1-3 m. tall; flowers white or pink) (Chokeberry) — 43.

42b. Mid-vein not glandular (shrubs or trees, 1-10 m. tall; flowers white) (Juneberry) — 44.

43a. Leaves glabrous beneath Chokeberry, Pyrus melanocarpa.

43b. Leaves tomentose beneath Chokeberry, Pyrus arbutifolia var. atropurpurea.

44a. Petals 15-25 mm. long — 45.

44b. Petals 5-12 mm. long — 46.

45a. Mature leaves glabrous Juneberry, Amelanchier canadensis.

45b. Mature leaves pubescent beneath Juneberry, Amelanchier canadensis var. botryapium.

46a. Flowers in racemes — 47.

46b. Flowers solitary, or in small clusters of 2-4 Juneberry, Amelanchier oligocarpa.

47a. Leaves coarsely dentate, with about 1 tooth for each lateral vein Juneberry, Amelanchier spicata.

47b. Leaves finely serrate, with about 2-3 teeth for each lateral vein Juneberry, Amelanchier oblongifolia.

48a. Flowers yellow — 49.

48b. Flowers white, pink, purple, or rose, never yellow — 63.

49a. Plant with basal trifoliate leaves, resembling strawberry (1-3 dm. high; late spring) Barren Strawberry, Waldsteinia fragarioides.

49b. Plants with leafy stems — 50.

50a. Flowers solitary in the axils of foliage leaves, on long peduncles (trailing or creeping plants; flowers in late spring and summer) — 51.

50b. Flowers in narrow terminal spike-like racemes (3-8 dm. high; summer) (Agrimony) — 52.

50c. Flowers in irregular or spreading clusters — 55.

51a. Leaflets 5 Five-finger, Potentilla canadensis.

51b. Leaflets 7-25 Silver Weed, Potentilla anserina.

52a. Principal leaflets more than 3 times (about 3-1/2) as long as wide Agrimony, Agrimonia parviflora.

52b. Principal leaflets less than 3 times (about 2-1/2) as long as wide — 53.

53a. Leaves nearly glabrous beneath, or with scattered spreading hairs Agrimony, Agrimonia gryposepala.

53b. Leaves softly pubescent beneath — 54.

54a. Leaves distinctly glandular beneath Agrimony, Agrimonia striata.

54b. Leaves not glandular beneath Agrimony, Agrimonia mollis.

55a. Principal leaves palmately compound with 5-7 leaflets (Cinquefoil) — 56.

55b. Principal stem-leaves with 3 leaflets, or pinnately compound with several leaflets — 58.

56a. Leaves silvery-white beneath, laciniately toothed (1-4 dm. high; late spring and summer) Silvery Cinquefoil, Potentilla argentea.

56b. Leaves not silvery-white beneath (3-10 dm. high; summer) — 57.

57a. Terminal leaflet more than 3 times as long as wide Cinquefoil, Potentilla recta.

57b. Terminal leaflet less than 3 times as long as wide Cinquefoil, Potentilla intermedia

58a. Flowers about 4 mm. wide (2-6 dm. high; spring) Spring Avens, Geum vernum.

58b. Flowers 6 mm. wide, or wider — 59.

59a. Principal leaves with lobed leaflets, of which the terminal is the largest; leaf-axis bearing also some small leaflets between those of usual size (4-12 dm. high; late spring and summer) (Avens) — 60.

59b. Principal leaves with toothed or pinnately cleft leaflets, the lateral ones about equaling the terminal one in size, and without any small scattered leaflets (3-8 dm. tall; summer) (Cinquefoil) — 61.

60a. Terminal leaflet cordate at base Avens, Geum macrophyllum.

60b. Terminal leaflet wedge-shape or acute at base Avens, Geum strictum.

61a. Leaflets 3 Cinquefoil, Potentilla monspeliensis.

61b. Leaflets 5-15 — 62.

62a. Leaflets crenate Cinquefoil, Potentilla paradoxa.

62b. Leaflets deeply incised Cinquefoil, Potentilla pennsylvanica.

63a. Leaves all basal, the flowers on leafless stalks — 64.

63b. Stem-leaves present — 66.

64a. Leaves simple (1-2 dm. high; summer) Dalibarda, Dalibarda repens.

64b. Leaves trifoliate (1-2 dm. high; spring) (Strawberry) — 65.

65a. Leaflets thick and firm, the petioles and pedicels pubescent with spreading or ascending hairs; fruit subglobose, the achenes embedded in pits on its surface Strawberry, Fragaria virginiana.

65b. Leaflets thin, the petioles and pedicels nearly glabrous or with appressed hairs; fruit conic, the achenes on its surface Wood Strawberry, Fragaria americana.

66a. Leaves pinnate with numerous leaflets — 67.

66b. Stem-leaves with 3-5 leaflets — 72.

67a. Leaflets laciniate or deeply lobed (flowers pink or purple, early summer) — 68.

67b. Leaflets merely toothed — 69.

68a. Stem-leaves few, small and opposite (2-4 dm. tall) Purple Avens, Geum triflorum.

68b. Stem-leaves large and alternate (5-20 dm. tall) Queen of the Prairie, Filipendula rubra.

69a. Individual flowers small, not exceeding 6 mm. across, in large clusters or spikes — 70.

69b. Individual flowers more than 10 mm. wide, in few-flowered clusters (Cinquefoil) — 71.

70a. Flowers in dense spikes (5-15 dm. high; late summer) Burnet, Sanguisorba canadensis.

70b. Flowers in panicles Sorbaria, Sorbaria sorbifolia.

71a. Flowers red or purple (3-6 dm. high; summer) Marsh Cinquefoil, Potentilla palustris.

71b. Flowers white (5-10 dm. high; early summer) Cinquefoil, Potentilla arguta.

72a. Pistils 5 (5-10 dm. high; flowers white or pink, early summer) — 73.

72b. Pistils 10, in a ring (flowers pink or purple) — 68b.

72c. Pistils numerous, in a head or close group — 74.

73a. Stipules linear or subulate, 5-8 mm. long Bowman's Root, Gillenia trifoliata.

73b. Stipules leaf-like, 10-25 mm. long, serrate American Ipecac, Gillenia stipulata.

74a. Flowers red or purple — 75.

74b. Flowers white — 76.

75a. Leaflets sharply and irregularly toothed or lobed; petals erect, narrowed at the base (3-9 dm. high; early summer) Purple Avens, Geum rivale.

75b. Leaflets finely and regularly toothed, oblong; petals spreading — 71a.

76a. Leaflets entire below, 3-toothed at the apex (1-3 dm. high; summer) Cinquefoil, Potentilla tridentata.

76b. Leaflets toothed all around the margin — 77.

77a. Leaves all trifoliate (2-5 dm. high; late spring) — 17b.

77b. Some of the upper leaves merely lobed or dentate (5-8 dm. high) (Avens) — 78.

78a. Stem bristly-hairy (early summer) Avens, Geum virginianum.

78b. Stem softly and finely pubescent (summer) Avens, Geum canadense.

LEGUMINOSAE, the Pulse Family

Trees, shrubs, or herbs, with alternate compound (except 3 species with simple) leaves and stipules; flowers usually irregular (except in a few species), with a large upper petal and 4 smaller ones, the 2 lower enclosing the stamens and pistil; stamens almost always 10, and generally united by their filaments; pistil 1, simple, ripening into a pod.

1a. Shrubs or trees — 2.

1b. Herbs, twining, but without tendrils — 9.

1c. Herbs; the leaves, or some of them, tipped with tendrils — 12.

1d. Herbs, not climbing or twining; tendrils none — 21.

2a. Leaves simple — 3.

2b. Leaves compound — 4.

3a. Leaves broadly cordate (tall shrub or small tree; flowers pink, early spring) Redbud, Cercis canadensis.

3b. Leaves lanceolate or elliptical (3-6 dm. high; flowers yellow, summer) Dyer's Greenweed, Genista tinctoria.

4a. Twigs or branches thorny — 5.

4b. Thorns none — 7.

5a. Thorns branched, scattered on the stem (tall tree; flowers greenish, early summer) Honey Locust, Gleditsia triacanthos.

5b. Thorns unbranched, a pair of them at the base of each leaf (late spring) — 6.

6a. Branches glabrous or nearly so (tree; flowers white) Black Locust, Robinia pseudo-acacia.

6b. Branches glandular-pubescent (tall shrub; flowers pinkish) Clammy Locust, Robinia viscosa.

6c. Branches bristly (shrub. 1-3 m. high; flowers pink) Bristly Locust, Robinia hispida.

7a. Trees; leaves 2-3-pinnate (flowers greenish-white, spring) Kentucky Coffee-tree, Gymnocladus dioica.

7b. Low shrubs; leaves once-pinnate (3-6 dm. high; summer) — 8.

8a. Flowers bright-blue, each with a single petal Lead Plant, Amorpha canescens.

8b. Flowers yellowish and pink-purple, petals 5 — 26a.

9a. Leaflets 5-7; flowers in racemes (purplish, late summer) Wild Bean, Apios tuberosa.

9b. Leaflets 3 (flowers greenish, purple, or white, late summer) — 10.

10a. Flowers in small capitate clusters; lower 2 petals strongly incurved Wild Bean, Strophostyles helvola.

10b. Flowers in racemes (Hog Peanut) — 11.

11a. Stem pubescent or glabrate; leaflets seldom more than 5 cm. long Hog Peanut, Amphicarpa monoica.

11b. Stem villous with retrorse hairs; leaflets usually longer than 5 cm. Hog Peanut, Amphicarpa pitcheri.

12a. Style with a tuft of hairs at the apex; lateral petals of the corolla adherent to the lower ones as far as the middle; stipules less than 10 mm. long, and usually less than one-fourth the length of the lower leaflets (spring and summer) (Vetch) — 13.

12b. Style hairy along the inner side; lateral petals of the corolla free from the lower ones or adherent only at the very base; stipules more than 8 mm. long and usually one-third or more the length of the lower leaflets (late spring and summer) — 17.

13a. Flowers axillary, sessile or nearly so (flowers purple) — 14.

13b. Flowers in peduncled racemes — 15.

14a. Upper leaves oblong-obovate, truncate or notched, and mucronate at the apex Spring Vetch, Vicia sativa.

14b. Upper leaves lance-linear, sharply acute Common Vetch, Vicia angustifolia.

15a. Flowers 15-20 mm. long, 4-8 in a cluster (flowers purple) Vetch, Vicia americana.

15b. Flowers 8-12 mm. long — 16.

16a. Racemes one-sided; flowers blue Vetch, Vicia cracca.

16b. Racemes loosely flowered, not one-sided; flowers whitish, the lower petals tipped with blue Vetch, Vicia caroliniana.

17a. Flowers yellowish-white Vetchling, Lathyrus ochroleucus.

17b. Flowers purple — 18.

18a. Stipules nearly regularly halberd-shape, almost as large as the leaflets Beach Pea, Lathyrus maritimus.

18b. Stipules half-sagittate, apparently attached laterally near the middle — 19.

19a. Leaflets 4-8 pairs, ovate; racemes with 10 or more flowers Wild Pea, Lathyrus venosus.

19b. Leaflets 2-4 pairs, linear to oblong or elliptical; racemes with 2-9 flowers (Marsh Pea) — 20.

20a. Stems with a membranous wing on the margins Marsh Pea, Lathyrus palustris.

20b. Stems angled, but not winged Marsh Pea, Lathyrus palustris var. myrtifolius.

21a. Leaves simple (2-3 dm. high; flowers yellow, summer) Rattlebox, Crotalaria sagittalis.

21b. Leaves palmately compound; leaflets 7-11 (3-6 dm. high; flowers blue, late spring) Lupine, Lupinus perennis.

21c. Leaves pinnately compound; leaflets 5 to many — 22.

21d. Leaves compound; leaflets 3 — 28.

22a. Leaflets 5; flowers rose-purple in a spike-like head (5-8 dm. high, late summer) Prairie Clover, Petalostemum purpureum.

22b. Leaflets more than 5 — 23.

23a. Flowers bright-blue, in a dense spike (3-6 dm. high; summer) — 8a.

23b. Flowers bright-yellow; stamens not united (summer) — 24.

23c. Flowers white, cream-color, or yellowish, or marked with purple — 26.

24a. Leaflets linear-oblong, 2 cm. long or less; stamens 5 or 10 (3-6 dm. high) (Partridge Pea) — 25.

24b. Leaflets lanceolate-oblong, 2-5 cm. long; 7 stamens with normal anthers and 3 with imperfect anthers (8-15 dm. high) Wild Senna, Cassia marilandica.

25a. Anthers 10; flowers 2-4 cm. wide Partridge Pea, Cassia chamaecrista.

25b. Anthers 5; flowers 5-10 mm. wide Partridge Pea, Cassia nictitans.

26a. Silky-hairy with whitish hairs; flowers marked with purple (3-5 dm. high; summer) Goat's Rue, Tephrosia virginiana.

26b. Glabrous or nearly so (summer) (Milk Vetch) — 27.

27a. Flowers greenish cream-color (4-10 dm. high) Milk Vetch, Astragalus canadensis.

27b. Flowers white (3-5 dm. high) Milk Vetch, Astragalus neglectus.

28a. Flowers in heads, umbels, or short dense spikes — 29.

28b. Flowers in loose racemes or panicles — 42.

29a. Flowers bright-yellow; decumbent or ascending plants (spring and summer) — 30.

29b. Flowers white, cream, purple, or red; never yellow — 34.

30a. Whole flower only about 2 mm. long; pod coiled — 31.

30b. Flowers larger, each one 3-6 mm. long; pod straight (1-4 dm. high) (Hop Clover) — 32.

31a. Flowers numerous in each head Black Medick, Medicago lupulina.

31b. Flowers in clusters of 2 — 20 Bur Clover, Medicago hispida.

32a. Stipules linear Hop Clover, Trifolium agrarium.

32b. Stipules ovate — 33.

33a. Heads densely flowered; flowers 20 or more; upper petal striate when dry Hop Clover, Trifolium procumbens.

33b. Heads loosely flowered; flowers usually 10 or fewer; upper petal scarcely striate or not at all Hop Clover, Trifolium dubium.

34a. Leaves palmately compound, the 3 leaflets all from the same point (late spring and summer) (Clover) — 35.

34b. Leaves pinnately compound, the terminal leaflet on a distinct stalk — 39.

35a. Individual flowers sessile, or on very short pedicels — 36.

35b. Individual flowers distinctly pedicelled — 37.

36a. Heads oblong, on distinct peduncles; calyx longer than the corolla (flowers nearly white; 1-4 dm. tall) Stone Clover, Trifolium arvense.

36b. Heads nearly globose, almost sessile, closely subtended by the leaves; corolla longer than the calyx (2-8 dm. high; flowers red-purple) Red Clover, Trifolium pratense.

37a. Stems prostrate or creeping; heads long-peduncled, arising from the creeping branches (flower-stalks 1-2 dm. high; flowers white) White Clover, Trifolium repens.

37b. Some or all of the stems erect; heads arising from the leafy stems (flowers white or pink) — 38.

38a. Plants with long basal runners; flowers 10-13 mm. long (2-3 dm. high) Buffalo Clover, Trifolium stoloniferum.

38b. Basal runners none; flowers 6-8 mm. long (3-8 dm. high) Alsike Clover, Trifolium hybridum.

39a. Prostrate; leaflets broadly ovate; flowers 3-10 in a cluster — 10a.

39b. Erect; leaflets broadest near the middle; flowers numerous (5-12 dm. high; flowers yellowish-white, late summer) (Bush Clover) — 40.

40a. Leaflets less than twice as long as broad Bush Clover, Lespedeza hirta.

40b. Leaflets more than twice as long as broad — 41.

41a. Leaflets linear, 5 mm. wide or less; heads with obvious peduncles Bush Clover, Lespedeza angustifolia.

41b. Leaflets narrowly elliptical, the principal ones more than 5 mm. wide; heads sessile or nearly so Bush Clover, Lespedeza capitata.

42a. Leaflets finely toothed — 43.

42b. Leaflets entire — 44.

43a. Flowers violet or blue (3-6 dm. high; summer) Alfalfa, Medicago sativa.

43b. Flowers yellow (1-2 m. high; summer) Yellow Sweet Clover, Melilotus officinalis.

43c. Flowers white (1-3 m. high; summer) White Sweet Clover, Melilotus alba.

44a. Flowers yellow (5-10 dm. high; summer) Wild Indigo, Baptisia tinctoria.

44b. Flowers white, the leaflets all from the same point (5-10 dm. high; summer) Wild Indigo, Baptisia leucantha.

44c. Flowers blue, purple, or pink (rarely white, and then the terminal leaflet stalked) — 45.

45a. Racemes arising from the base of the plant, leafless (4-8 dm. high; summer) Tick Trefoil, Desmodium nudiflorum.

45b. Racemes terminal or a few of them axillary; leaflets generally more than 3 cm. long; pod (usually to be seen at the base of the raceme) transversely segmented into 2 or more joints (summer) (Tick Trefoil; the genus Desmodium. Pods are usually necessary for satisfactory identification) — 46.

45c. Racemes short, loose, chiefly axillary; leaflets generally less than 3 cm. long; the short ovate or ovoid pod not transversely jointed (5-10 dm. high; flowers in summer) (Bush Clover; the genus Lespedeza. Reference to the Manual is recommended) — 58.

46a. Leaves clustered near the summit of the stem (4-12 dm. high) Tick Trefoil, Desmodium grandiflorum.

46b. Leaves scattered on the stem — 47.

47a. Plants prostrate; racemes panicled; leaflets nearly circular Tick Trefoil, Desmodium rotundifolium.

47b. Plants decumbent or ascending; racemes short, simple, few-flowered; stipules ovate (stems 4-8 dm. long) Tick Trefoil, Desmodium pauciflorum.

47c. Plants erect or ascending; racemes panicled — 48.

48a. Leaflets of an oblong type, broadest at or near the middle, and about 4 times as long as broad (5-10 dm. tall) — 49.

48b. Leaflets of an ovate or lanceolate type, broadest below the middle, and not more than 3 times as long as wide — 50.

49a. Stem pubescent; leaves sessile or nearly so Tick Trefoil, Desmodium sessilifolium.

49b. Stem glabrous or nearly so; leaves obviously petioled Tick Trefoil, Desmodium paniculatum.

50a. Stipules lanceolate to ovate, 1 cm. long or more (6-15 dm. high) — 51.

50b. Stipules narrowly lanceolate or subulate, less than 1 cm. long — 54.

51a. Stems glabrous or minutely pubescent; leaves acuminate — 52.

51b. Stems hispid or densely pubescent; leaves ovate or ovate-lanceolate, obtuse or barely acute — 53.

52a. Leaves glabrous on both sides Tick Trefoil, Desmodium bracteosum.

52b. Leaves rough above, hairy beneath Tick Trefoil, Desmodium bracteosum var. longifolium.

53a. Leaflets broadly ovate Tick Trefoil, Desmodium canescens.

53b. Leaflets ovate-lanceolate Tick Trefoil, Desmodium illinoense.

54a. Flowers 10-12 mm. long (1-2 m. high) Tick Trefoil, Desmodium canadense.

54b. Flowers 5-8 mm. long (5-8 dm. tall) — 55.

54c. Flowers 3-4 mm. long (4-8 dm. tall) — 56.

55a. Leaflets broadly ovate Tick Trefoil, Desmodium viridiflorum.

55b. Leaflets oblong-ovate Tick Trefoil, Desmodium dillenii.

56a. Leaflets 3-5 cm. long, oblong-ovate, scabrous above Tick Trefoil, Desmodium rigidum.

56b. Leaflets 1-2.5 cm. long, broadly ovate or oval, not scabrous above — 57.

57a. Stem and leaves glabrous or very nearly so Tick Trefoil, Desmodium marilandicum.

57b. Stem and leaves conspicuously pubescent Tick Trefoil, Desmodium obtusum.

58a. Flower-clusters sessile, or on peduncles shorter than the subtending leaves — 59.

58b. Flower-clusters, or many of them, on peduncles longer than the leaves — 61.

59a. Leaves linear-oblong Bush Clover, Lespedeza virginica.

59b. Leaves ovate or oval — 60.

60a. Leaves and stem velvety or downy Bush Clover, Lespedeza stuvei.

60b. Leaves and stem glabrous, or with close appressed pubescence Bush Clover, Lespedeza frutescens.

61a. Leaves ovate or broadly elliptical; corolla conspicuously exceeding the calyx — 62.

61b. Leaves linear-oblong; calyx about as long as the corolla Bush Clover, Lespedeza manniana.

62a. Stem erect or ascending — 63.

62b. Stem trailing; peduncles much exceeding the leaves Bush Clover, Lespedeza procumbens.

63a. Villous-pubescent; inflorescence dense; some peduncles shorter than the leaves Bush Clover, Lespedeza nuttallii.

63b. Slightly pubescent or glabrous; inflorescence loose, on peduncles much longer than the leaves Bush Clover, Lespedeza violacea.

LINACEAE, the Flax Family

Herbs with simple leaves, and regular flowers, having 5 sepals, 5 yellow or blue petals, 5 stamens, and 5 styles.

1a. Flowers blue (3-6 dm. high; summer) Flax, Linum usitatissimum.

1b. Flowers yellow (3-8 dm. high; summer) (Wild Flax) — 2.

2a. Middle stem-leaves below the branches opposite Wild Flax, Linum striatum.

2b. Middle stem-leaves below the branches alternate — 3.

3a. Leaves narrowly lanceolate to linear, 1-4 mm. wide — 4.

3b. Leaves oblanceolate to oblong, 4-6 mm. wide Wild Flax, Linum virginianum.

4a. Leaves entire Wild Flax, Linum medium.

4b. Upper leaves glandular-ciliate Wild Flax, Linum sulcatum.

OXALIDACEAE, the Wood Sorrel Family

Herbs, with alternate or basal compound leaves with 3 reverse heart-shaped leaflets; sepals, petals, and styles each 5; stamens 10. (Wood Sorrel)

1a. Leaves all basal; flowers white to pink-purple (1-2 dm. high; late spring) — 2.

1b. Stem-leaves present; flowers yellow (1-5 dm. high; spring and summer) — 3.

2a. Flower-stalks bearing a single flower Wood Sorrel, Oxalis acetosella.

2b. Flower-stalks bearing an umbel of several flowers Wood Sorrel, Oxalis violacea.

3a. Stem prostrate and creeping Wood Sorrel, Oxalis repens.

3b. Stem erect or ascending — 4.

4a. Pedicels with spreading pubescence Wood Sorrel, Oxalis corniculata.

4b. Pedicels with appressed pubescence Wood Sorrel, Oxalis stricta.

GERANIACEAE, the Geranium Family

Herbs, with deeply lobed or divided leaves; flowers regular, with 5 sepals, 5 petals, 5 or 10 stamens, and a 5-celled ovary.

1a. Anthers 5 (spreading or ascending plants, 2-4 dm. high; flowers pink or purple, spring and summer) — 2.

1b. Anthers 10 — 3.

2a. Leaves pinnately dissected Stork's-bill, Erodium cicutarium.

2b. Leaves palmately divided into cuneate lobes Crane's-bill, Geranium pusillum.

3a. Leaves ternately divided, the lobes pinnatifid (2-4 dm. high; flowers purple, late spring and summer) Herb Robert, Geranium robertianum.

3b. Leaves palmately 3-11-lobed — 4.

4a. Petals 12 mm. long or more (3-6 dm. high; flowers pale purple, spring) Wild Geranium, Geranium maculatum.

4b. Petals less than 10 mm. long (Crane's-bill) — 5.

5a. Seed-bearing portion of the pistil smooth, glabrous or nearly so (low spreading plant; flowers purple, late spring and summer) Crane's-bill, Geranium columbinum.

5b. Seed-bearing portion of the pistil transversely wrinkled (widely branching. 1-3 dm. tall; flowers purple, summer) Crane's-bill, Geranium molle.

5c. Seed-bearing portion of the pistil pubescent (widely branching. 1-5 dm. tall) — 6.

6a. Leaves divided almost to the base (flowers pinkish or white, spring and summer) — 7.

6b. Leaves divided one-half to two-thirds the way to the base (flowers purple, summer) Crane's-bill, Geranium rotundifolium.

7a. Petals white or pale pink; flowers in compact clusters Crane's-bill, Geranium carolinianum.

7b. Petals pink-purple; flowers in loose clusters Crane's-bill, Geranium bicknellii.

RUTACEAE, the Rue Family

Shrubs or low trees, with compound leaves frequently dotted with translucent glands; flowers small, greenish-white, with 3-5 sepals, petals, and stamens.

1a. Leaflets 5-9; stems thorny Prickly Ash, Zanthoxylum americanum.

1b. Leaflets 3; stems not thorny Hop Tree, Ptelea trifoliata.

SIMARUBACEAE, the Quassia Family

Trees, with pinnately compound leaves and small greenish-yellow flowers in large panicles in early summer, ripening into winged fruits.

One species in Michigan, escaped from cultivation chiefly in towns Tree of Heaven, Ailanthus glandulosa.

POLYGALACEAE, the Milkwort Family

Small herbs, with alternate or whorled simple leaves, and small irregular flowers; sepals 5, petals 3, stamens 6 or 8, more or less united with each other and with the petals.

1a. All of the leaves alternate — 2.

1b. Some or all of the leaves in whorls (1-4 dm. high; flowers greenish, purple, or white; summer) (Milkwort) — 6.

2a. Flowers few, loosely clustered, 15-20 mm. long (1-3 dm. high; flowers purple; early summer) Flowering Wintergreen, Polygala paucifolia.

2b. Flowers numerous, in a spike or raceme — 3.

3a. Stem-leaves minute, linear-subulate; stem slender, erect, 3-7 dm. high (flowers pink; summer) Milkwort, Polygala incarnata.

3b. Stem-leaves narrowly oblong or broader; stem generally 1-4 dm. high — 4.

4a. Flowers in a short thick obtuse very dense spike (flowers greenish or purple; summer) Milkwort, Polygala sanguinea.

4b. Flowers in a slender tapering spike — 5.

4c. Flowers in a raceme; plants with subterranean flowers also (flowers purple; early summer) Milkwort, Polygala polygama.

5a. Leaves linear or nearly so (flowers purple; summer) — 7b.

5b. Leaves lanceolate or oblong-lanceolate, 2-6 cm. long (flowers white; late spring) Seneca Snakeroot, Polygala senega.

5c. Leaves ovate to ovate-lanceolate (flowers white; late spring) Seneca Snakeroot, Polygala senega var. latifolia.

6a. Spike oval, thick, obtuse Milkwort, Polygala cruciata.

6b. Spike acute — 7.

7a. Spike densely flowered, 1-2 cm. long Milkwort, Polygala verticillata.

7b. Spike loosely flowered, 2-5 cm. long Milkwort, Polygala verticillata var. ambigua.

EUPHORBIACEAE, the Spurge Family

Herbs, with alternate, opposite, or whorled leaves and usually milky juice. Flowers small or minute and inconspicuous, without petals and frequently without calyx. In our commoner species, several staminate flowers, each consisting of a single stamen only, and one pistillate flower, consisting of a single pedicelled 3-lobed ovary only, are included within a 4-5-lobed involucre, which is sometimes colored and resembles a calyx or corolla.

1a. Stem-leaves alternate; inflorescence axillary; flowers with calyx and several stamens (3-8 dm. tall; flowers greenish or purplish; summer) (Three-seeded Mercury) — 2.

1b. Stem-leaves opposite, usually inequilateral at base; flowers as described for the family; apparent flowers in axillary clusters (summer and autumn) (Spurge) — 3.

1c. Stem-leaves alternate; inflorescence a terminal umbel-like cluster, with its branches subtended by opposite or whorled leaves; flowers as described for the family (Spurge) — 9.

2a. Leaves ovate or ovate-lanceolate; flower-clusters shorter than the subtending bract Three-seeded Mercury, Acalypha virginica.

2b. Leaves lanceolate to oblong; flower-clusters equaling or exceeding the subtending bract Three-seeded Mercury, Acalypha gracilens.

3a. Stem and foliage glabrous — 4.

3b. Stem and foliage more or less pubescent (stems prostrate or ascending, 1-4 dm. long) — 7.

4a. Erect or ascending, usually without basal branches (2-4 dm. tall) Spurge, Euphorbia preslii.

4b. Prostrate or spreading, branched from the base (stems 1-4 dm. long) — 5.

5a. Leaves entire; plants of the shores of the Great Lakes Spurge, Euphorbia polygonifolia.

5b. Leaves serrulate — 6.

6a. Leaves broadly oblong or obovate; seeds obscurely wrinkled Spurge, Euphorbia serpyllifolia.

6b. Leaves narrowly oblong; seeds with prominent transverse ridges Spurge, Euphorbia glyptosperma.

7a. Seeds black Spurge, Euphorbia hirsuta.

7b. Seeds red — 8.

8a. Leaves oblong Spurge, Euphorbia maculata.

8b. Leaves elliptical to obovate; involucre split down one side Spurge, Euphorbia humistrata.

9a. Flowers subtended by conspicuous petal-like white appendages (part of the involucre) (4-10 dm. tall; summer) Spurge, Euphorbia corollata.

9b. Flowers not subtended by petal-like appendages — 10.

10a. Stem-leaves below the inflorescence serrulate (2-5 dm. high; summer) — 11.

10b. Stem-leaves below the inflorescence entire — 13.

11a. Upper leaves acute Spurge, Euphorbia platyphylla.

11b. Upper leaves obtuse, rounded, or notched at the apex — 12.

12a. Leaves of the involucre broadly triangular-ovate, widest near the base Spurge, Euphorbia obtusata.

12b. Leaves of the involucre broadly obovate to nearly circular, widest near or above the middle Spurge, Euphorbia helioscopia.

13a. Stem-leaves narrowly linear, less than 3 mm. wide (2-4 dm. high; late spring and summer) Cypress Spurge, Euphorbia cyparissias.

13b. Stem-leaves narrowly oblong-spatulate, more than 5 mm. wide, and more than 3 times as long as wide (2-6 dm. high; summer) — 14.

13c. Stem-leaves obovate to nearly circular, not more than twice as long as wide (1-4 dm. high) — 15.

14a. Leaves at base of umbel narrow, resembling those on the stem Spurge, Euphorbia esula.

14b. Leaves at base of umbel broad, resembling those of the inflorescence Spurge, Euphorbia lucida.

15a. Upper stem-leaves distinctly narrowed at the base; introduced species of waste places (summer) Spurge, Euphorbia peplus.

15b. Upper stem-leaves rounded at the sessile base; native species of woodlands (spring and early summer) Spurge, Euphorbia commutata.

CALLITRICHACEAE, the Water Starwort Family

Small herbs growing in water or in mud, with opposite entire leaves and small inconspicuous axillary flowers, with neither calyx nor corolla. (Flowers in summer).

1a. Completely submerged; leaves all linear Water Starwort, Callitriche autumnalis.

1b. Submerged leaves linear, emersed and floating leaves obovate Water Starwort, Callitriche palustris.

EMPETRACEAE, the Crowberry Family

Low evergreen shrubs, with the linear leaves completely rolled into a tube, and inconspicuous flowers without petals, in the axils of the leaves.

One species in Michigan, 1-3 dm. high; leaves less than 1 cm. long; flowers in summer Crowberry, Empetrum nigrum.

LIMNANTHACEAE, the False Mermaid Family

Low herbs with alternate compound leaves and minute axillary flowers; sepals 3, petals 3, stamens 6.

One species in Michigan, with stems 1-3 dm. long, and flowers in late spring False Mermaid, Floerkea proserpinacoides.

ANACARDIACEAE, the Cashew Family

Shrubs or small trees, with milky or resinous juice, alternate compound leaves sometimes poisonous to the touch, and small clustered greenish or yellowish flowers.

1a. Leaflets 7 to many (1-5 m. high) (Sumach) — 2.

1b. Leaflets 3-5.

2a. Axis of the leaves wing-margined between the leaflets Sumach, Rhus copallina.

2b. Axis of the leaves not margined — 3.

3a. Leaflets entire Poison Sumach, Rhus vernix.

3b. Leaflets serrate — 4.

4a. Bark of the older stems glabrous Sumach, Rhus glabra.

4b. Bark of the older stems densely velvety-hairy Sumach, Rhus typhina.

5a. Terminal leaflet narrowed to a sessile base (5-20 dm. high) Sumach, Rhus canadensis.

5b. Terminal leaflet on a definite stalk, round or acute at base (3-8 dm. high, or climbing by hold-fast roots) Poison Ivy, Rhus toxicodendron.

AQUIFOLIACEAE, the Holly Family

Shrubs, with alternate simple leaves and small white or greenish axillary flowers in late spring and early summer; sepals, petals, and stamens each 4-6; fruit a berry.

1a. Leaves entire or nearly so, 1-3 cm. long (1-2 m. tall) Mountain Holly, Nemopanthus mucronata.

1b. Leaves sharply serrate, 5-8 cm. long (2-5 m. high) (Black Alder) — 2.

2a. Leaves downy on the veins beneath; fruit red Black Alder, Ilex verticillata.

2b. Leaves nearly or quite glabrous; fruit orange Black Alder, Ilex verticillata var. tenuifolia.

CELASTRACEAE, the Staff Tree Family

Shrubs with simple leaves and inconspicuous flowers; sepals and petals each 4 or 5, the stamens of the same number and attached to a disk which fills the center of the flower; fruit showy, orange and red.

1a. Leaves alternate (climbing vine; flowers in racemes; late spring) Bitter-sweet, Celastrus scandens.

1b. Leaves opposite (flowers in axillary clusters) — 2.

2a. Prostrate, with short erect branches; leaves broadest above the middle (spring) Creeping Wahoo, Evonymus obovatus.

2b. Tall shrub, with leaves broadest below or near the middle (early summer) Wahoo, Evonymus atropurpureus.

STAPHYLEACEAE, the Bladder Nut Family

Shrubs with opposite trifoliate leaves and small axillary clusters of white flowers in spring; sepals, petals, and stamens each 5; ovary 3-celled, ripening into a large inflated 3-celled pod.

One species in Michigan (2-5 m. high) Bladder Nut, Staphylea trifolia.

ACERACEAE, the Maple Family

Trees or shrubs, with opposite, lobed or compound leaves and inconspicuous flowers; sepals about 5; petals the same number, or none; stamens 4-12; ovary 2-lobed, ripening into a pair of winged fruits.

1a. Leaves compound (tree; flowers appearing before the leaves) Box Elder, Acer negundo.

1b. Leaves simple (Maple) — 2.

2a. Shrubs or small trees; leaves 3-5-lobed; the lobes with regularly serrate margins (flowers greenish-yellow, appearing later than the leaves) — 3.

2b. Trees; leaves 3-7-lobed; margins of the lobes entire or incised, but never regularly serrate — 4.

3a. Leaves finely and sharply serrate; twigs smooth; bark conspicuously striped with white lines Striped Maple, Acer pennsylvanicum.

3b. Leaves coarsely and bluntly serrate; young twigs pubescent; bark not striped Mountain Maple, Acer spicatum.

4a. Angles between the leaf-lobes rounded (flowers greenish-yellow, appearing with the leaves) — 5.

4b. Angles between the leaf-lobes acute or obtuse, but not rounded (flowers purple, red, or yellowish, appearing before the leaves) — 6.

5a. Leaves glabrous beneath, or minutely pubescent on the veins Sugar Maple, Acer saccharum.

5b. Leaves downy beneath Black Maple, Acer saccharum var. nigrum.

6a. Middle leaf-lobe usually more than half the length of the leaf, narrowed at its base; broken twigs with a strong odor Silver Maple, Acer saccharinum.

6b. Middle leaf-lobe usually less than half the length of the leaf, its sides parallel or broadened at the base; broken twigs without strong odor Red Maple, Acer rubrum.

SAPINDACEAE, the Soapberry Family

Trees, with opposite palmately compound leaves, and showy white or yellowish flowers in panicles in spring; sepals 5; petals 4 or 5; stamens about 7; fruit a smooth brown nut.

1a. Leaflets 7; buds viscid; corolla of 5 petals Horse Chestnut, Aesculus hippocastanum.

1b. Leaflets 5; buds smooth; corolla of 4 petals Buckeye, Aesculus glabra.

BALSAMINACEAE, the Touch-me-not Family

Smooth herbs, with alternate simple leaves and showy flowers; one petal-like sepal prolonged into a spur; fruit explosive when ripe (5-10 dm. high; summer).

1a. Flowers pale-yellow, with a few red-brown spots Touch-me-not, Impatiens pallida.

1b. Flowers orange, thickly spotted with red-brown Touch-me-not, Impatiens biflora.

RHAMNACEAE, the Buckthorn Family

Shrubs, with simple leaves and small flowers in axillary or terminal clusters in early summer; sepals, petals, and stamens each 4 to 5, or petals none.

1a. Leaves with a single mid-vein; flowers in axillary clusters, greenish (Buckthorn) — 2.

1b. Leaves with 3-5 principal veins; flowers in dense terminal clusters, white (Red-root) — 3.

2a. Lateral veins 3-4 pairs (stout shrub, frequently thorny, escaped from cultivation) Buckthorn, Rhamnus cathartica.

2b. Lateral veins 6-9 pairs (1 m. high or less; in swamps and bogs) Buckthorn, Rhamnus alnifolia.

3a. Leaves ovate, rounded or cordate at the base, 2-5 cm. wide or more (4-8 dm. high) Red-root, Ceanothus americanus.

3b. Leaves elliptical-lanceolate, 2 cm. wide or less (3-8 dm. high) Red-root, Ceanothus ovatus.

VITACEAE, the Grape Family

Shrubs, climbing by tendrils or hold-fast roots, with palmately lobed or palmately compound leaves and small greenish flowers in panicles or flattened clusters; petals and sepals each 4 or 5; fruit a berry.

1a. Leaves compound (summer) (Virginia Creeper) — 2.

1b. Leaves simple (late spring) (Grape) — 4.

2a. Branches of the tendrils chiefly ending in adhesive disks — 3.

2b. Branches of the tendrils twining, or rarely with a few disks Virginia Creeper, Psedera vitacea.

3a. Stem and foliage glabrous Virginia Creeper, Psedera quinquefolia.

3b. Stem and foliage pubescent, at least when young Virginia Creeper, Psedera quinquefolia var. hirsuta.

4a. Leaves conspicuously pubescent beneath — 5.

4b. Leaves glabrous beneath when mature, or pubescent on the veins only — 6.

5a. A tendril or flower-cluster opposite each leaf Fox Grape, Vitis labrusca.

5b. No tendril opposite each third leaf Summer Grape, Vitis aestivalis.

6a. Pith continuous through the joints of the stem Fox Grape, Vitis rotundifolia.

6b. Pith interrupted by the solid joints — 7.

7a. Leaf-lobes with rounded angles between them Summer Grape, Vitis bicolor.

7b. Leaf-lobes with sharp angles between them — 8.

8a. Leaves coarsely toothed, unlobed or slightly 3-lobed Frost Grape, Vitis cordifolia.

8b. Leaves sharply toothed, prominently lobed Frost Grape, Vitis vulpina.

TILIACEAE, the Linden Family

Trees, with alternate, simple, palmately veined leaves, and clusters of fragrant white flowers in late spring arising from the middle of a leaf-like bract; sepals and petals each 5; stamens numerous, but united into 5 sets.

One species in Michigan Basswood, Tilia americana.

MALVACEAE, the Mallow Family

Herbs with alternate leaves; sepals and petals each 5; stamens numerous, united by their filaments to form a tube surrounding the styles; ovary many-celled.

1a. Flowers yellow (summer and autumn) — 2.

1b. Flowers pale-yellow, with a dark center (2-4 dm. high; late summer) Flower-of-an-hour, Hibiscus trionum.

1c. Flowers white to red or blue, never yellow — 3.

2a. Leaves broadly heart-shape (10-15 dm. tall) Velvet Leaf, Abutilon theophrasti.

2b. Leaves ovate-lanceolate (2-5 dm. tall) Sida, Sida spinosa.

3a. Calyx subtended by 6 to many bractlets which are sometimes united at base (summer) — 4.

3b. Calyx subtended by 3 bractlets, or by none — 6.

4a. Flowers 2-4 cm. wide (5-10 dm. high; flowers pink) Marsh Mallow, Althaea officinalis.

4b. Flowers 7-15 cm. wide (8-15 dm. high; flowers pink to nearly white) (Rose Mallow) — 5.

5a. Leaves densely pubescent below Rose Mallow, Hibiscus moscheutos.

5b. Leaves glabrous Rose Mallow, Hibiscus militaris.

6a. Petals prominently notched at the end or reverse heart-shape (Mallow) — 7.

6b. Petals obtuse or truncate (summer) — 11.

7a. Flowers 1-1.5 cm. wide — 8.

7b. Flowers 2-5 cm. wide (3-8 dm. high; flowers in summer) — 9.

8a. Stems procumbent, prostrate, or spreading (spring, summer, and autumn) Mallow, Malva rotundifolia.

8b. Stems erect (10-15 dm. high; summer) Mallow, Malva verticillata.

9a. Leaves with prominent but shallow lobes; flowers axillary Mallow, Malva sylvestris.

9b. Leaves deeply lobed or cleft; flowers in the upper axils, producing a raceme-like cluster — 10.

10a. Lobes of the leaf dentate or incised Mallow, Malva alcea.

10b. Lobes of the leaf pinnately cleft into linear or narrowly oblong divisions Mallow, Malva moschata.

11a. Flowers white (1-2 m. high) Virginia Mallow, Sida hermaphrodita.

11b. Flowers purple or pink (3-5 dm. high, spreading) Poppy Mallow, Callirhoe triangulata.

HYPERICACEAE, the St. John's-wort Family

Herbs or shrubs, with opposite entire leaves dotted with translucent glands; flowers usually yellow (or pink); sepals and petals each 5; stamens 5 to many; ovary with 3-5 styles. (St. John's-wort.)

1a. Shrubs (4-8 dm. high; flowers yellow, summer) — 2.

1b. Herbs (flowers in summer) — 3.

2a. Styles 5 St. John's-wort, Hypericum kalmianum.

2b. Styles 3 St. John's-wort, Hypericum prolificum.

3a. Flowers pinkish, 15 mm. broad (3-5 dm. high, in swamps) Marsh St. John's-wort, Hypericum virginicum.

3b. Flowers yellow — 4.

4a. Flowers about 4 cm. wide; principal leaves 5-10 cm. long (7-15 dm. tall) St. John's-wort, Hypericum ascyron.

4b. Flowers 8-25 mm. wide; stamens 15 or more — 5.

4c. Flowers 1-10 mm. wide; stamens 12 or fewer (1-6 dm. high) — 7.

5a. Petals dotted with black (4-8 dm. high) — 6.

5b. Petals without black dots (2-5 dm. high) St. John's-wort, Hypericum ellipticum.

6a. Flowers 20-25 mm. wide; leaves of an oblong type, broadest near the middle St. John's-wort, Hypericum perforatum.

6b. Flowers 10-15 mm. wide; leaves of an ovate type, broadest below the middle St. John's-wort, Hypericum punctatum.

7a. Leaves minute, subulate, 1-3 mm. long Pineweed, Hypericum gentianoides.

7b. Leaves linear, with 1-3 principal veins, broadest near or above the middle St. John's-wort, Hypericum canadense.

7c. Leaves lanceolate, 4-6 times as long as broad, with 5-7 principal veins St. John's-wort, Hypericum majus.

7d. Leaves oblong, elliptic, or ovate, 1.5-3 times as long as broad — 8.

8a. Uppermost bracts linear St. John's-wort, Hypericum mutilum.

8b. Uppermost bracts resembling the leaves in shape, but smaller St. John's-wort, Hypericum boreale.

ELATINACEAE, the Waterwort Family

Small marsh herbs, with opposite leaves without translucent dots, and inconspicuous axillary flowers. (Stems 2-5 cm. long; flowers in summer.)

One species in Michigan Waterwort, Elatine americana.

CISTACEAE, the Rock-rose Family

Small herbs or shrubs, with opposite or alternate entire leaves; flowers regular, with 5 sepals, 3 or 5 petals, and 3 to many stamens.

1a. Flowers yellow (early summer) — 2.

1b. Flowers greenish or purplish, minute, in panicles (late summer) (Pinweed) — 4.

2a. Leaves crowded, closely appressed to the branches; flowers 7 mm. wide (2-4 dm. high) False Heather, Hudsonia tomentosa.

2b. Leaves spreading; flowers 15-30 mm. wide (3-6 dm. high) (Frostweed) — 3.

3a. Petal-bearing flowers solitary Frostweed, Helianthemum canadense.

3b. Petal-bearing flowers few, racemose Frostweed, Helianthemum majus.

4a. Stem-leaves linear, 4 or more times as long as wide — 5.

4b. Stem-leaves oblong or elliptical, about 3 times as long as wide (2-6 dm. tall) — 8.

5a. Plant pale with dense appressed pubescence (2-4 dm. high) Pinweed, Lechea stricta.

5b. Plant green, pubescence sparse or none — 6.

6a. Leaves thread-like, seldom exceeding 1 mm. in width (1-3 dm. tall) Pinweed, Lechea tenuifolia.

6b. Leaves 1-5 mm. wide (2-6 dm. high) — 7.

7a. Leaves on the basal shoots narrowly lanceolate Pinweed, Lechea intermedia.

7b. Leaves on the basal shoots oblong-elliptic, about twice as long as wide Pinweed, Lechea racemulosa.

8a. Pubescence of spreading hairs Pinweed, Lechea villosa.

8b. Pubescence of appressed hairs Pinweed, Lechea minor.

VIOLACEAE, the Violet Family

Herbs with simple, alternate or basal leaves, and conspicuous irregular flowers with a spur (except in the first species); sepals, petals, and stamens each 5; ovary 1-celled.

1a. Flowers regular or nearly so, greenish-white, axillary; erect plant with leafy stem (3-5 dm. high; spring) Green Violet, Hybanthus concolor.

1b. Flowers irregular, blue, yellow, or white, conspicuous (Violet) — 2.

2a. Plant stemless, the flowers all on leafless stalks and the leaves all basal (spring or early summer) — 3.

2b. Stems leafy (spring and summer) — 17.

3a. Petals yellow Round-leaved Violet, Viola rotundifolia.

3b. Petals blue, violet, or white — 4.

4a. Principal leaves at time of flowering deeply lobed — 5.

4b. Leaves oblong, ovate, or triangular, not narrowed to the petiole, and frequently sharply toothed or incised near the base — 7.

4c. Leaves narrowly lanceolate, tapering to the base Violet, Viola lanceolata.

4d. Leaves heart-shape or kidney-shape, not lobed — 8.

5a. Lateral petals bearded — 6.

5b. Lateral petals not bearded Bird-foot Violet, Viola pedata.

6a. Leaves divided to the base into linear segments Bird-foot Violet, Viola pedatifida.

6b. Leaves irregularly divided into broader segments Hand-leaf Violet, Viola palmata.

7a. Leaves ovate-oblong, pubescent Violet, Viola fimbriatula.

7b. Leaves triangular-lanceolate, usually somewhat dilated at base, nearly or quite glabrous Violet, Viola sagittata.

8a. Flowers violet or blue (rarely white-flowered plants are found with the typical blue-flowered ones) (Blue Violets) — 9.

8b. Flowers white, the 3 lower petals marked with purple (White Violets) — 14.

9a. Lateral petals bearded — 10.

9b. Lateral petals beardless Great-spurred Violet, Viola selkirkii.

10a. Foliage glabrous — 11.

10b. Petioles and lower surface of leaves pubescent — 13.

11a. Beard of the lateral petals with a knob at the tip of each hair Blue Violet, Viola cucullata.

11b. Beard of the lateral petals not knobbed — 12.

12a. Spurred petal hairy Wood Violet, Viola affinis.

12b. Spurred petal glabrous Blue Violet, Viola papilionacea.

13a. Spurred petal villous Blue Violet, Viola septentrionalis.

13b. Spurred petal glabrous, or with a few scattered hairs Common Blue Violet, Viola sororia.

14a. Leaf-blade obviously pubescent — 15.

14b. Leaf-blade glabrous or very nearly so — 16.

15a. Lateral petals bearded Sweet White Violet, Viola incognita.

15b. Lateral petals not bearded White Violet, Viola renifolia.

16a. Leaf-blades strictly glabrous Sweet White Violet; Viola pallens.

16b. Leaf-blades with some minute white hairs on the upper surface near the base Sweet White Violet, Viola blanda.

17a. Stipules large and leaf-like, deeply pinnatifid and nearly or quite as long as the petioles — 18.

17b. Stipules small, inconspicuous, entire or toothed, and much shorter than the petiole — 19.

18a. Leaves serrate; flowers 1.5-2.5 cm. wide (1-3 dm. high; flowers of various colors) Pansy, Viola tricolor.

18b. Upper leaves entire or nearly so; flowers about 1 cm. wide (1-2 dm. high; flowers bluish-white) Wild Pansy, Viola rafinesquii.

19a. Petals yellow (1-4 dm. high) (Yellow Violet) — 20.

19b. Petals violet, blue, or white — 21.

20a. Foliage villous-pubescent Yellow Violet, Viola pubescens.

20b. Foliage nearly or quite glabrous Yellow Violet, Viola scabriuscula.

21a. Stipules entire (2-4 dm. high) Canada Violet, Viola canadensis.

21b. Stipules toothed — 22.

22a. Lateral petals not bearded (1-2 dm. high) Long-spurred Violet, Viola rostrata.

22b. Lateral petals bearded — 23.

23a. Flowers white or nearly white (1-3 dm. high) Pale Violet, Viola striata.

23b. Flowers blue (about 1 dm. high) — 24.

24a. Leaves smooth Dog Violet, Viola conspersa.

24b. Leaves pubescent Sand Violet, Viola arenaria.

CACTACEAE, the Cactus Family

Fleshy, jointed leafless plants, armed with numerous thorns; flowers large (5-10 cm. wide), yellow, with about 10 petals and numerous stamens.

One species in Michigan, on the shores of Lake Michigan; flowers in summer Prickly Pear, Opuntia rafinesquii.

THYMELAEACEAE, the Mezereum Family

Shrubs, with simple alternate entire leaves, and small yellowish flowers in clusters, opening before the leaves; petals none, the sepals somewhat petal-like.

One species in Michigan, 5-15 dm. tall, with very tough bark Leatherwood, Dirca palustris.

ELAEAGNACEAE, the Oleaster Family

Shrubs, with opposite, silvery-pubescent, simple, entire leaves, and small clusters of inconspicuous yellow flowers in spring.

One species in Michigan, 1-2 m. high Buffalo Berry, Shepherdia canadensis.

LYTHRACEAE, the Loosestrife Family

Herbs or shrubs, with opposite or alternate entire leaves; receptacle cup-shape or tubular, bearing the 5-7 petals and sepals at its margin, and the 6-12 stamens on its inner surface; ovary superior.

1a. Stem shrubby (aquatic, stems 1-3 m. long; flowers pink, summer) Water Loosestrife, Decodon verticillatus.

1b. Stem herbaceous (4-10 dm. high; flowers purple, summer) — 2.

2a. Flowers solitary in the axils; leaves mostly alternate Loosestrife, Lythrum alatum.

2b. Flowers in terminal panicles; leaves opposite or whorled Loosestrife, Lythrum salicaria.

MELASTOMACEAE, the Melastoma Family

Herbs, with opposite leaves with 3-5 principal veins; receptacle urn-shape, bearing 4 sepals and 4 petals at its edge; stamens 8; ovary 4-celled, superior.

One species in Michigan, 3-4 dm. high, with purple flowers in late summer Meadow Beauty, Rhexia virginica.

ONAGRACEAE, the Evening Primrose Family

Herbs with opposite or alternate simple leaves and regular flowers; sepals and petals each 4 (or 2 in one genus), stamens 8 (or 2 in one genus), attached to the summit or inside of a tubular receptacle; ovary 2-4-celled, inferior.

1a. Aquatic plant of shallow water or muddy ground, with prostrate stem (flowers minute, axillary; petals small or none, summer) Water Purslane, Ludvigia palustris.

1b. Land plants with erect or ascending stems — 2.

2a. Petals minute, greenish (3-8 dm. high; late summer) False Loosestrife, Ludvigia polycarpa.

2b. Petals yellow — 3.

2c. Petals white, pink, purple, or red — 9.

3a. Sepals borne at the summit of the ovary (5-10 dm. high; summer) False Loosestrife, Ludvigia alternifolia.

3b. Sepals borne at the summit of the slender tubular receptacle, which is prolonged beyond the ovary — 4.

4a. Stamens all equal in length (Evening Primrose) — 5.

4b. The alternate stamens longer (3-8 dm. high; summer) (Sundrops) — 8.

5a. Leaves deeply dentate or pinnatifid (2-5 dm. high; early summer) Evening Primrose, Oenothera laciniata.

5b. Leaves entire or undulate or finely toothed (5-12 dm. high; summer) — 6.

6a. Hairs on the stem with broad reddish bases Evening Primrose, Oenothera muricata.

6b. Hairs on the stem none, or without swollen bases — 7.

7a. Stem and foliage glabrous, or with sparse spreading hairs Evening Primrose, Oenothera biennis.

7b. Stem and foliage densely but closely appressed-pubescent Evening Primrose, Oenothera rhombipetala.

8a. Petals 5-10 mm. long Sundrops, Oenothera pumila.

8b. Petals 14 mm. long or more Sundrops, Oenothera fruticosa.

9a. Petals 2, reverse heart-shape, stamens 2 (flowers small, white, summer) (Enchanter's Nightshade) — 10.

9b. Petals 4; stamens 4 or 8 — 12.

10a. Leaves rounded at the base, denticulate (3-8 dm. high; fruit prickly) Enchanter's Nightshade, Circaea lutetiana.

10b. Leaves cordate at the base — 11.

11a. Fruit 2-celled, bristly (2-4 dm. high) Enchanter's Nightshade, Circaea intermedia.

11b. Fruit 1-celled, with soft hairs (delicate plant 2 dm. high, or less) Enchanter's Nightshade, Circaea alpina.

12a. Petals entire (summer) — 13.

12b. Petals notched at the end (flowers white or pinkish, less than 1 cm. broad, in summer) (Willow Herb) — 15.

13a. Flowers 2-3 cm. wide, purple (7-20 dm. high) Fireweed, Epilobium angustifolium.

13b. Flowers about 1 cm. wide — 14.

14a. Flowers red (2-5 dm. high) Gaura, Gaura coccinea.

14b. Flowers white, turning pink when old Gaura, Gaura biennis.

15a. Leaves entire, the margins usually somewhat revolute — 16.

15b. Leaves toothed, flat (4-9 dm. high) — 18.

16a. Plant densely pubescent with spreading hairs (3-8 dm. high) Willow Herb, Epilobium molle.

16b. Plant pubescent with appressed or incurved hairs — 17.

17a. Leaves linear, the margin revolute (3-5 dm. high) Willow Herb, Epilobium densum.

17b. Leaves narrowly lanceolate, not revolute (2-4 dm. high) Willow Herb, Epilobium palustre.

18a. Seeds tipped with a tuft of reddish-brown hairs Willow Herb, Epilobium coloratum.

18b. Seeds tipped with a tuft of white hairs Willow Herb, Epilobium adenocaulon.

HALORAGIDACEAE, the Water Milfoil Family

Aquatic or marsh herbs, with alternate, opposite, or whorled leaves, and small, inconspicuous terminal or axillary flowers, frequently without petals (summer).

1a. Leaves none, or else very small and inconspicuous Water Milfoil, Myriophyllum tenellum.

1b. Leaves alternate (1-4 dm. high) Mermaid Weed, Proserpinaca palustris.

1c. Leaves opposite or whorled — 2.

2a. Leaves entire (2-4 dm. high) Mare's-tail, Hippuris vulgaris.

2b. Leaves toothed or dissected (Water Milfoil) — 3.

3a. Flowers in the axils of foliage leaves — 4.

3b. Flowers in terminal spikes, subtended by bracts — 5.

4a. Flowers above water, subtended by toothed or entire leaves Water Milfoil, Myriophyllum heterophyllum.

4b. Flowers submerged, subtended by dissected leaves Water Milfoil, Myriophyllum farwellii.

5a. Flowers solitary or in pairs at each joint of the spike Water Milfoil, Myriophyllum alternifolium.

5b. Flowers several at each joint of the spike — 6.

6a. Bracts deeply pinnatifid Water Milfoil, Myriophyllum verticillatum var. pectinatum.

6b. Bracts entire or toothed Water Milfoil, Myriophyllum spicatum.

ARALIACEAE, the Sarsaparilla Family

Herbs or thorny shrubs, with alternate or whorled leaves, and small flowers in umbels; sepals 5, minute; petals and stamens each 5; ovary inferior, with 2-5 styles, ripening into a berry.

1a. Leaves simple, palmately lobed (thorny shrub; flowers greenish-white, in panicles, in June) Devil's Club, Fatsia horrida.

1b. Leaves once compounded, whorled (umbel one, terminal) — 2.

1c. Leaves twice or thrice compounded (umbels several) — 3.

2a. Leaflets sessile; flowers white, in spring (1-2 dm. high) Dwarf Ginseng, Panax trifolium.

2b. Leaflets stalked; flowers greenish, in summer (2-5 dm. high) Ginseng, Panax quinquefolium.

3a. Stem and petioles spiny or bristly (flowers white, summer) — 4.

3b. Stem and petioles smooth or a little pubescent (flowers greenish-white) — 5.

4a. Shrubby, with stout thorns (1-3 m. high) Hercules' Club, Aralia spinosa.

4b. Herbaceous, with slender bristles (4-10 dm. high) Bristly Sarsaparilla, Aralia hispida.

5a. Stem-leaves present; leaflets cordate at the base (8-15 dm. high; summer) Spikenard, Aralia racemosa.

5b. Leaf and flower-stalk arising from the ground; leaflets acute at the base (2-4 dm. high; spring) Wild Sarsaparilla, Aralia nudicaulis.

UMBELLIFERAE, the Parsley Family

Herbs, with alternate, usually compound leaves, the petioles dilated at the base; flowers small, in umbels or heads; sepals 5, minute or even wanting; petals and stamens each 5; ovary inferior, with 2 styles, ripening into a dry fruit.

1a. Leaves simple (flowers in summer) — 2.

1b. Leaves compound, or at least deeply cleft — 4.

2a. Leaves linear, sword-shape (4-10 dm. tall; flowers greenish-white) Rattlesnake Master, Eryngium yuccifolium.

2b. Leaves kidney-shape or almost circular (stems creeping, about 1 dm. high; flowers white) (Water Pennywort) — 3.

3a. Leaves peltate, attached by the center Water Pennywort, Hydrocotyle umbellata.

3b. Leaves not peltate, attached by the margin Water Pennywort, Hydrocotyle americana.

4a. Flowers yellow or purple — 5.

4b. Flowers white or greenish — 13.

5a. Leaf-segments entire (4-8 dm. high) — 6.

5b. Leaf-segments toothed or incised — 7.

6a. Leaf-segments filiform (summer) Fennel, Foeniculum vulgare.

6b. Leaf-segments ovate to lanceolate Golden Alexander, Taenidia integerrima.

7a. Leaves pinnately compound; some of the leaflets incised or pinnatifid — 8.

7b. Leaves ternately compound; the segments crenate or serrate — 9.

7c. Leaves deeply palmately cleft or divided; flowers in head-like umbels — 18a.

8a. Leaf-segments obtuse, rounded, or cordate at the base (6-15 dm. high; summer) Wild Parsnip, Pastinaca sativa.

8b. Leaf-segments narrowed to the base (4-8 dm. high; spring) Prairie Parsley, Polytaenia nuttallii.

9a. Terminal leaflets conspicuously stalked, their total length, including stalk, at least 50% greater than the length of the lateral leaflets (Meadow Parsnip) — 10.

9b. Terminal leaflets not conspicuously stalked, their total length, including stalk, about equaling the lateral leaflets (4-8 dm. high; late spring) (Golden Alexander) — 12.

10a. Flowers purple (4-8 dm. high; early summer) Meadow Parsnip, Thaspium aureum var. atropurpureum.

10b. Flowers yellow — 11.

11a. Stem-leaves once-ternate; leaflets finely serrate (4-8 dm. high; early summer) Meadow Parsnip, Thaspium aureum.

11b. Many stem-leaves 2-3-ternate; leaflets coarsely serrate or incised (6-12 dm. high; early summer) Meadow Parsnip, Thaspium barbinode.

12a. Basal and lower stem-leaves 2-3-ternate Golden Alexander, Zizia aurea.

12b. Basal leaves simple; stem-leaves once-ternate Golden Alexander, Zizia cordata.

13a. Leaves once-pinnate (or the submerged leaves decompound, if present) (summer) — 14.

13b. Leaves ternately, palmately, or 2-3-pinnately compound — 16.

14a. Leaflets mostly ovate or ovate-lanceolate, some of them coarsely incised (3-9 dm. high) Water Parsnip, Berula erecta.

14b. Leaflets linear to oblong, serrate to nearly entire, not incised (6-15 dm. high) — 15.

15a. Leaflets entire, or with a few low remote teeth Cowbane, Oxypolis rigidior.

15b. Leaflets finely but sharply serrate Water Parsnip, Sium cicutaefolium.

16a. Leaves principally basal, decompound; flowers in early spring (1-2 dm. high) Harbinger of Spring, Erigenia bulbosa.

16b. Leaves principally on the stem — 17.

17a. Leaves palmately or ternately once-compound — 18.

17b. Leaves 2-3 times compound or decompound — 24.

18a. Flowers short-pedicelled, crowded in head-like umbels, greenish; ovary bristly (4-9 dm. high; early summer) (Black Snakeroot) — 19.

18b. Flowers in open umbels, white — 22.

19a. Styles short, not projecting beyond the bristles of the mature fruit — 20.

19b. Styles long, projecting beyond the bristles of the fruit, and recurved — 21.

20a. Staminate flowers on pedicels 3-4 mm. long, equaling or barely exceeding the fruit Black Snakeroot, Sanicula trifoliata.

20b. Staminate flowers short-pedicelled, concealed among the fruits Black Snakeroot, Sanicula canadensis.

21a. Fruit short-stalked, 4 mm. long or less Black Snakeroot, Sanicula gregaria.

21b. Fruit sessile, 6-7 mm. long Black Snakeroot, Sanicula marilandica.

22a. Umbel unsymmetrical, its branches irregular in length; plant slender (3-8 dm. tall; early summer) Honewort, Cryptotaenia canadensis.

22b. Umbel symmetrical with regular branches; plants tall and stout — 23.

23a. Stem and leaves very pubescent (10-25 dm. high; summer) Cow Parsnip, Heracleum lanatum.

23b. Stem and leaves glabrous or nearly so (5-15 dm. high; early summer) Masterwort, Imperatoria ostruthium.

24a. Ovary and fruit bristly (4-10 dm. high) — 25.

24b. Ovary and fruit smooth or winged, never bristly — 27.

25a. Umbels loose, open, few-flowered; woodland plants blooming in spring (Sweet Cicely) — 26.

25b. Umbels densely flowered; weedy plants blooming from summer to fall Wild Carrot, Daucus carota.

26a. Stem villous-pubescent Sweet Cicely, Osmorhiza claytoni.

26b. Stem glabrous except at the joints Sweet Cicely, Osmorhiza longistylis.

27a. Leaflets merely serrate (flowers in summer) — 28.

27b. Leaflets coarsely incised, so that the leaf appears dissected — 30.

28a. Umbel densely pubescent (8-15 dm. high) Angelica, Angelica villosa.

28b. Umbel smooth — 29.

29a. Leaf-segments broadly ovate (8-15 dm. high) Angelica, Angelica atropurpurea.

29b. Leaf-segments lanceolate (8-15 dm. high) Water Hemlock, Cicuta maculata.

29c. Leaf-segments linear (4-10 dm. high) Water Hemlock, Cicuta bulbifera.

30a. Principal branches of the umbel 2-5; fruit linear-oblong; woodland plants blooming in spring (2-4 dm. high) Chervil, Chaerophyllum procumbens.

30b. Principal branches of the umbel 7 or more; fruit ovate to broadly elliptical (summer) — 31.

31a. Native plants, growing in swamps (5-15 dm. high) Hemlock Parsley, Conioselinum chinense.

31b. Introduced plants, in waste places and along roads — 32.

32a. Stems conspicuously spotted with purple (5-15 dm. high) Poison Hemlock, Conium maculatum.

32b. Stems not spotted with purple (2-5 dm. high) Caraway, Carum carvi.

CORNACEAE, the Dogwood Family

Trees, shrubs, or herbs, with alternate leaves and small flowers in rather crowded rounded or flattened clusters; sepals 4, minute; petals and stamens each 4; ovary inferior, ripening into a berry. In one genus the flowers are minute and greenish, with 5 sepals and petals minute or none.

1a. Leaves alternate — 2.

1b. Leaves opposite — 3.

2a. Flowers white, conspicuous, in flattened clusters (shrubs 2-4 m. high; flowers in late spring) Dogwood, Cornus alternifolia.

2b. Flowers greenish, inconspicuous, in small axillary clusters (tree; flowers in spring) Sour Gum, Nyssa sylvatica.

3a. Flower clusters small and dense, surrounded by a showy involucre of 4 bracts, resembling a corolla of 4 petals — 4.

3b. Flowers in open flattened clusters, without petal-like involucre (shrubs 1-4 m. high; late spring) — 5.

4a. Herbaceous, 3 dm. high or less (flowers in late spring) Dwarf Dogwood, Cornus canadensis.

4b. Tall shrub or tree (flowers in late spring) Flowering Dogwood, Cornus florida.

5a. Leaves distinctly pubescent beneath with woolly or spreading hairs — 6.

5b. Leaves smooth beneath, or pubescent with short appressed hairs — 9.

6a. Leaves rough above; fruit white Dogwood, Cornus asperifolia.

6b. Leaves smooth or finely soft-hairy above — 7.

7a. Leaves at least twice as long as wide; branches brownish or purplish — 8.

7b. Leaves less than twice as long as wide; branches greenish; fruit blue Dogwood, Cornus circinata.

8a. Branches purplish; fruit blue Dogwood, Cornus amomum.

8b. Branches brownish; fruit white Dogwood, Cornus baileyi.

9a. Branches bright red or reddish-purple Dogwood, Cornus stolonifera.

9b. Branches grayish Dogwood, Cornus paniculata.

ERICACEAE, the Heath Family

Herbs or shrubs, frequently with evergreen leaves; sepals 4-5; corolla regular, with 4-5 petals; stamens as many or twice as many; ovary 3-10-celled, with 1 style.

1a. Plants without green color; leafless or with scale leaves only — 2.

1b. Plants with green leaves — 4.

2a. Flowers solitary (1-2 dm. high; summer) Indian Pipe, Monotropa uniflora.

2b. Flowers in clusters — 3.

3a. Petals united into a bell-shape corolla (3-9 dm. high; summer) Pine Drops, Pterospora andromedea.

3b. Petals all separate (1-3 dm. high; summer) Beech Drops, Monotropa hypopitys.

4a. Leaves all basal; herbaceous plants with terminal racemes (1-4 dm. high; summer) (Shin-leaf) — 5.

4b. Stem-leaves present — 12.

5a. Style straight — 6.

5b. Style bent near the apex — 8.

6a. Racemes one-sided, the flowers all turned in one direction (flowers white or greenish-white) — 7.

6b. Raceme regular, the flowers not all pointing in the same direction (flowers white or pink) Shin-leaf, Pyrola minor.

7a. Flowers numerous in each raceme Shin-leaf, Pyrola secunda.

7b. Flowers only 3-7 in each raceme Shin-leaf, Pyrola seconda var. obtusata.

8a. Flowers pink or purple — 9.

8b. Flowers white or greenish — 10.

9a. Leaves cordate at base Shin-leaf, Pyrola asarifolia.

9b. Leaves rounded at base, not cordate Shin-leaf, Pyrola asarifolia var. incarnata.

10a. Leaves shining on the upper side; sepals one-third as long as the petals Shin-leaf, Pyrola americana.

10b. Leaves dull on the upper side; sepals one-fourth as long as the petals, or a little shorter — 11.

11a. Leaf-blades mostly shorter than their petioles, thick and firm Shin-leaf, Pyrola chlorantha.

11b. Leaf-blades thin, usually longer than their petioles Shin-leaf, Pyrola elliptica.

12a. Petals nearly or quite separate from each other — 13.

12b. Petals united into a gamopetalous corolla, the tube of which is as long as or longer than the lobes — 18.

13a. Leaves opposite or whorled; stems herbaceous or nearly so (summer) — 14.

13b. Leaves alternate; stems shrubby (early summer) — 16.

14a. Flowers solitary; leaves broadly ovate to nearly circular (1 dm. high; flower white) One-flowered Wintergreen, Moneses uniflora.

14b. Flowers in clusters; leaves narrow (stems trailing, 1-3 dm. high; flowers white or pinkish) — 15.

15a. Leaves broadest above the middle, green Prince's Pine, Chimaphila umbellata.

15b. Leaves broadest below the middle, spotted with white Spotted Wintergreen, Chimaphila maculata.

16a. Leaves 2-5 cm. long, densely woolly beneath (5-10 dm. high; flowers white) Labrador Tea, Ledum groenlandicum.

16b. Leaves 1-2 cm. long, pale beneath but not wholly (creeping; flowers pink) (Cranberry) — 17.

17a. Leaves acute Cranberry, Vaccinium oxycoccos.

17b. Leaves obtuse Cranberry, Vaccinium macrocarpon.

18a. Leaves opposite or whorled; corolla saucer-shape (shrubs 3-8 dm. high; flowers purple, summer) — 19.

18b. Leaves alternate; corolla bell-shape or salver-form — 20.

19a. Branches and twigs cylindrical, not angled Sheep Laurel, Kalmia angustifolia.

19b. Branches and twigs with 2 sharp angles Swamp Laurel, Kalmia polifolia.

20a. Plants prostrate, or with a few ascending branches only (flowers white or pink) — 21.

20b. Plants erect or ascending — 23.

21a. Flowers 10-20 mm. long, very fragrant (early spring) Trailing Arbutus, Epigaea repens.

21b. Flowers 4-5 mm. long (late spring) — 22.

22a. Leaves spatulate, broadest beyond the middle Bearberry, Arctostaphylos uva-ursi.

22b. Leaves oval, broadest at the middle Snowberry, Chiogenes hispidula.

23a. Leaves linear, white beneath, their margins strongly revolute (shrub 3-8 dm. high; flowers white, late spring) Bog Rosemary, Andromeda glaucophylla.

23b. Leaves oblong, scurfy beneath with rusty scales (bog shrub 4-10 dm. high; flowers white, in spring) Leatherleaf, Chamaedaphne calyculata.

23c. Leaves smooth, pubescent, or resinous beneath, but not scurfy nor white — 24.

24a. Low shrubs 10-15 cm. high, erect from a creeping rootstock; leaves with the taste of wintergreen (flowers white or pink, summer) Wintergreen, Gaultheria procumbens.

24b. Bushy shrubs 3-8 dm. high; leaves dotted beneath with yellowish resinous dots; ovary 10-celled (flowers greenish-pink, spring) Huckleberry, Gaylussacia baccata.

24c. Shrubs 1 dm. to 3 m. high; leaves not resinous-dotted beneath; ovary 5-celled (flowers white or greenish-pink, spring or early summer) — 25.

25a. Corolla bell-shape, the stamens projecting beyond it (5-15 dm. high) Deerberry, Vaccinium stamineum.

25b. Corolla cylindrical or urn-shape, the stamens not projecting — 26.

26a. Filaments hairy (Blueberry) — 27.

26b. Filaments glabrous (Bilberry) — 32.

27a. Low bushy shrubs, usually less than 5 dm. and never more than 1 m. high — 28.

27b. Tall erect shrubs, 1-4 m. high — 31.

28a. Foliage pubescent Blueberry, Vaccinium canadense.

28b. Foliage glabrous — 29.

29a. Leaves pale-green and glaucous, entire or nearly so Blueberry, Vaccinium vacillans.

29b. Leaves bright-green, distinctly serrulate — 30.

30a. Fruit blue Blueberry, Vaccinium pennsylvanicum.

30b. Fruit black Blueberry, Vaccinium pennsylvanicum var. nigrum.

31a. Leaves downy beneath; fruit black Blueberry, Vaccinium atrococcum.

31b. Leaves smooth or minutely pubescent beneath; fruit blue Blueberry, Vaccinium corymbosum.

32a. Full-grown leaves less than 2.5 cm. long; low much-branched shrubs, mostly less than 5 dm. high — 33.

32b. Full-grown leaves more than 2.5 cm. long; shrubs usually a meter high or more — 34.

33a. Leaves entire; petals usually 4. Bilberry, Vaccinium uliginosum.

33b. Leaves finely serrulate; petals 5 Bilberry, Vaccinium caespitosum.

34a. Leaves serrulate, green beneath, acute; corolla globular Bilberry, Vaccinium membranaceum.

34b. Leaves entire, pale beneath, obtuse; corolla ovoid Bilberry, Vaccinium ovalifolium.

PRIMULACEAE, the Primrose Family

Herbs, with alternate or opposite simple leaves and regular flowers; petals more or less united; stamens attached one in front of each petal; ovary 1-celled with 1 style.

1a. Leaves all basal; flowers on leafless stalks — 2.

1b. Stem-leaves present — 5.

2a. Flowers nodding, the petals reflexed (3-6 dm. high; flowers showy, white or pink, in spring) Shooting Star, Dodecatheon meadia.

2b. Flowers erect or spreading; petals not reflexed — 3.

3a. Corolla not longer than the calyx; flowers small and inconspicuous (1 dm. high; flowers white or pink, spring) Androsace, Androsace occidentalis.

3b. Corolla conspicuous, much longer than the calyx (flowers pink or purple, summer) (Primrose) — 4.

4a. Leaves white-mealy beneath (1-4 dm. high) Primrose, Primula farinosa.

4b. Leaves green beneath (2 dm. high or less) Primrose, Primula mistassinica.

5a. All the stem-leaves in one whorl just below the flower-cluster — 6.

5b. Stem-leaves several or many, scattered over the stem — 7.

6a. Stem-leaves about 1 cm. long — 3a.

6b. Stem-leaves 5-10 cm. long Star Flower, Trientalis americana.

7a. Flowers red, blue, or white (summer) — 8.

7b. Flowers yellow (summer) — 9.

8a. Leaves opposite; flowers axillary (stems spreading, 1-4 dm. long; flowers blue or red) Pimpernel, Anagallis arvensis.

8b. Leaves alternate; flowers racemose (1-4 dm. high; flowers minute, white) Water Pimpernel, Samolus floribundus.

9a. Stem creeping Moneywort, Lysimachia nummularia.

9b. Stem erect (Loosestrife) — 10.

10a. Flowers in dense spike-like racemes (3-8 dm. high) Loosestrife, Lysimachia thyrsiflora.

10b. Flowers axillary or racemose (3-9 dm. high) — 11.

11a. Corolla dotted or streaked with purple or brown; leaves punctate with dark spots — 12.

11b. Corolla plain yellow; leaves not dark-dotted — 14.

12a. Flowers in racemes — 13.

12b. Flowers all axillary Loosestrife, Lysimachia quadrifolia.

13a. Flowers all in racemes; leaves opposite or some of them alternate Loosestrife, Lysimachia terrestris.

13b. The lowest flowers axillary; leaves opposite or whorled Loosestrife, Lysimachia producta.

14a. Leaves ovate, on slender ciliate petioles Loosestrife, Steironema ciliatum.

14b. Leaves lanceolate, sessile or short-petioled, pinnately veined Loosestrife, Steironema lanceolatum.

14c. Leaves linear, with one mid-vein Loosestrife, Steironema quadriflorum.

OLEACEAE, the Olive Family

Trees or shrubs, with opposite leaves and regular flowers; sepals 4, or calyx none; petals 4, united, or none; stamens usually 2; ovary 2-celled, superior.

1a. Leaves simple (shrub 2-5 m. high; flowers blue or white, in showy clusters in spring) Lilac, Syringa vulgaris.

1b. Leaves compound (trees; flowers greenish, inconspicuous, in spring) (Ash) — 2.

2a. Lateral leaflets sessile Black Ash, Fraxinus nigra.

2b. Lateral leaflets stalked — 3.

3a. Twigs sharply 4-angled Blue Ash, Fraxinus quadrangulata.

3b. Twigs not distinctly angled — 4.

4a. Leaves pubescent beneath Red Ash, Fraxinus pennsylvanica.

4b. Leaves glabrous beneath — 5.

5a. Leaves pale-green beneath, obscurely serrulate White Ash, Fraxinus americana.

5b. Leaves bright-green beneath, sharply serrulate Green Ash, Fraxinus pennsylvanica var. lanceolata.

GENTIANACEAE, the Gentian Family

Herbs, with opposite or basal, entire, usually simple leaves and regular flowers; sepals, petals, and stamens equal in number, 4-12; ovary superior, 1-celled.

1a. Leaves reduced to small scales (1-4 dm. high; flowers small, greenish-yellow, in summer) Bartonia, Bartonia virginica.

1b. Leaves rounded, floating (flowers white, summer) Floating Heart, Nymphoides lacunosum.

1c. Leaves compound (2-4 dm. high; flowers white or bluish, early summer) Buckbean, Menyanthes trifoliata.

1d. Leaves simple, whorled (1-2 m. high; flowers yellowish-white, summer) American Columbo, Frasera caroliniensis.

1e. Leaves simple, opposite — 2.

2a. Corolla rotate, with spreading lobes, 2-4 cm. broad, pink (5-8 dm. high; summer) Rose Pink, Sabbatia angularis.

2b. Corolla bell-shape, each petal with a spur at the base, purplish or white, and not over 1 cm. long (1-4 dm. high; summer) Spurred Gentian, Halenia deflexa.

2c. Corolla bell-shape, tubular, funnel-form, or salver-form, not spurred — 3.

3a. Corolla-lobes fringed (flowers bright-blue) (Fringed Gentian) — 4.

3b. Corolla-lobes entire — 5.

4a. Leaves lanceolate (2-8 dm. high; autumn) Fringed Gentian, Gentiana crinita.

4b. Leaves linear (1-4 dm. high; late summer) Fringed Gentian, Gentiana procera.

5a. Corolla 2 cm. long or a little less — 6.

5b. Corolla 2.5-5 cm. long (late summer and autumn) (Gentian) — 7.

6a. Upper leaves linear or narrowly lanceolate (2-4 dm. high; flowers pink-purple, late summer) Centaury, Centaurium umbellatum.

6b. Upper leaves ovate, with several principal veins (1-5 dm. high; flowers blue, late summer and autumn) Gentian, Gentiana quinquefolia.

7a. Calyx-lobes rough or ciliate at the margin (flowers blue, or rarely white) — 8.

7b. Calyx-lobes smooth (2-8 dm. high) — 10.

8a. Corolla-lobes spreading; leaves narrowly lanceolate, indistinctly veined (2-5 dm. high) Gentian, Gentiana puberula.

8b. Corolla-lobes erect or incurved; leaves ovate to ovate-lanceolate, with 3-7 principal veins (3-6 dm. high) — 9.

9a. Calyx-lobes equaling or exceeding the calyx-tube Gentian, Gentiana saponaria.

9b. Calyx-lobes shorter than the calyx-tube Gentian, Gentiana andrewsii.

10a. Leaves ovate or ovate-lanceolate, somewhat cordate at base (flowers greenish-white or yellowish-white) Gentian, Gentiana flavida.

10b. Leaves narrowly lanceolate or nearly linear, not cordate (flowers blue) Gentian, Gentiana linearis.

APOCYNACEAE, the Dogbane Family

Herbs, with opposite simple entire leaves and regular flowers; sepals, petals, and stamens each 5; petals united; stamens attached to the corolla; ovaries 2, with a single style or stigma.

1a. Plant creeping or trailing; flowers blue, axillary, 2-3 cm. broad (spring) Periwinkle, Vinca minor.

1b. Plant erect or essentially so; flowers 1 cm. broad or less (4-12 dm. high) — 2.

2a. Corolla pinkish, about 8 mm. long by 6-8 mm. broad (early summer) Dogbane, Apocynum androsaemifolium.

2b. Corolla white or greenish, about 6 mm. long by 4 mm. broad (summer) — 3.

3a. Leaves petioled, acute at the base Indian Hemp, Apocynum cannabinum.

3b. Leaves sessile, rounded or truncate at the base Indian Hemp, Apocynum cannabinum var. hypericifolium.

ASCLEPIADACEAE, the Milkweed Family

Herbs, with simple entire leaves and regular flowers; juice usually milky; except in the first species, which is a twining vine. The flowers have an unusual structure: calyx of 5 sepals; petals 5, united with each other, and spreading or reflexed so that they conceal the calyx; stamens 5, united with each other and with the stigma to form a complex organ in the center of the flower; ovaries 2; on the back of each stamen is a colored projecting hood, which is frequently the most conspicuous part of the flower, and may be mistaken for the corolla.

1a. Twining vine, with dark purple flowers (summer) Black Swallow-wort, Cynanchum nigrum.

1b. Stems not twining — 2.

2a. Leaves whorled (3-6 dm. high; summer) (Milkweed) — 3.

2b. Leaves opposite or alternate — 4.

3a. Leaves in whorls of 4, lanceolate (flowers pink) Milkweed, Asclepias quadrifolia.

3b. Leaves in whorls of 4-7, linear (flowers greenish-white) Milkweed, Asclepias verticillata.

4a. Umbel sessile (4-8 dm. high; flowers green, summer) Green Milkweed, Acerates viridiflora.

4b. Umbel peduncled — 5.

5a. Leaves linear or narrowly linear-lanceolate (4-8 dm. high; flowers greenish-white, summer) Green Milkweed, Acerates floridana.

5b. Leaves lanceolate or broader (flowers in summer) — 6.

6a. Leaves pubescent beneath — 7.

6b. Leaves glabrous or nearly so — 10.

7a. Flowers brilliant orange (3-6 dm. high) Butterfly Weed, Asclepias tuberosa.

7b. Flowers red or purple — 8.

8a. Reflexed lobes of corolla merely purple-tinged (1-2 m. high) Milkweed, Asclepias syriaca.

8b. Reflexed lobes of corolla bright-red or purple — 9.

9a. The erect hoods of each flower about 5 mm. long (7-12 dm. high) Milkweed, Asclepias purpurascens.

9b. The erect hoods of each flower about 3 mm. long (6-10 dm. high) Swamp Milkweed, Asclepias incarnata var. pulchra.

10a. Leaves broadly rounded and almost sessile at base (flowers purplish) — 11.

10b. Leaves narrowed at the base, distinctly petioled (8-15 dm. high) — 12.

11a. Umbel solitary, terminal and erect on a long peduncle (4-8 dm. high) Milkweed, Asclepias amplexicaulis.

11b. Umbels terminal or lateral, bent toward one side (7-12 dm. high) Milkweed, Asclepias sullivantii.

12a. Corolla (not hoods) red (1-2 m. high) Swamp Milkweed, Asclepias incarnata.

12b. Corolla (not hoods) greenish (8-15 dm. high) Milkweed, Asclepias exaltata.

CONVOLVULACEAE, the Morning Glory Family

Twining or trailing herbs (except one species), with regular flowers; sepals 5; corolla 5-angled or 5-lobed; stamens 5, attached to the corolla; ovary superior, 2-3-celled.

1a. Plants with green foliage and conspicuous flowers (summer) — 2.

1b. Leafless brown or yellow plants, with very small flowers (Dodder) — 7.

2a. Style divided at the top into linear or oblong stigmas (flowers white or pink) (Bindweed) — 3.

2b. Style not divided at the top; stigmas sessile, capitate (Morning Glory) — 6.

3a. Stem erect; leaves rounded or somewhat cordate at base, not hastate or sagittate (1-3 dm. high) Bindweed, Convolvulus spithamaeus.

3b. Stem trailing or twining; leaves sagittate or hastate — 4.

4a. Calyx almost concealed by two large heart-shape bracts — 5.

4b. Bracts at base of calyx none Bindweed, Convolvulus arvensis.

5a. Leaves triangular-hastate, with sharp basal lobes Bindweed, Convolvulus sepium.

5b. Leaves oblong-ovate, the basal lobes obtuse Bindweed, Convolvulus sepium var. pubescens.

6a. Stem smooth or nearly so; ovary 2-celled (flowers white) Wild Potato Vine, Ipomoea pandurata.

6b. Stem with reflexed hairs; ovary 3-celled (flowers of various colors) Morning Glory, Ipomoea purpurea.

7a. Introduced weed, growing as a parasite on clover Dodder, Cuscuta epithymum.

7b. Native species, on various shrubs and herbs — 8.

8a. Flowers sessile — 9.

8b. Flowers distinctly pedicelled — 12.

9a. Sepals united below into a gamosepalous calyx — 10.

9b. Sepals separate from each other — 11.

10a. Calyx-lobes obtuse Dodder, Cuscuta arvensis.

10b. Calyx-lobes acute Dodder, Cuscuta obtusiflora.

11a. Flowers in dense rope-like twists on various species of herbs Dodder, Cuscuta paradoxa.

11b. Flowers in dense clusters on various species of shrubs Dodder, Cuscuta compacta.

12a. Tips of the petals inflexed Dodder, Cuscuta coryli.

12b. Tips of the petals erect or spreading — 13.

13a. Capsule depressed at the summit Dodder, Cuscuta cephalanthi.

13b. Capsule pointed at the summit Dodder, Cuscuta gronovii.

POLEMONIACEAE, the Polemonium Family

Herbs with alternate or opposite leaves and conspicuous regular flowers; sepals 5, united; petals 5, united and bearing the 5 stamens in the corolla-tube; ovary superior, 3-celled.

1a. Leaves pinnately compound and alternate (2-4 dm. high; flowers blue, in spring) Greek Valerian, Polemonium reptans.

1b. Leaves fascicled, narrowly linear (about 1 dm. high; flowers pink-purple, in spring) Moss Pink, Phlox subulata.

1c. Leaves simple, strictly opposite — 2.

2a. Corolla-lobes deeply 2-cleft to the middle (1-2 dm. high; flowers pink, in spring) Cleft Phlox, Phlox bifida.

2b. Corolla-lobes entire and rounded, or somewhat notched at the apex — 3.

3a. Flowers in summer (8-15 dm. high; flowers purple) Garden Phlox, Phlox paniculata.

3b. Flowers in spring (3-6 dm. high) — 4.

4a. Corolla blue-purple; stems ascending Sweet William, Phlox divaricata.

4b. Corolla pink or red-purple; stems erect Sweet William, Phlox pilosa.

HYDROPHYLLACEAE, the Water-leaf Family

Herbs with alternate lobed or divided leaves and regular flowers; sepals 5; petals 5, united; stamens 5, attached to the corolla-tube and projecting beyond it; ovary 1-celled.

1a. Leaves palmately veined and lobed (4-8 dm. high; flowers purple, early summer) Water-leaf, Hydrophyllum canadense.

1b. Leaves pinnately veined and lobed (2-6 dm. high; flowers blue or purple, varying to white) — 2.

2a. Corolla-lobes much shorter than the corolla-tube (summer) Phacelia, Phacelia franklinii.

2b. Corolla-lobes much longer than the corolla-tube (late spring and summer) (Water-leaf) — 3.

3a. Calyx with a small reflexed appendage between each pair of sepals Water-leaf, Hydrophyllum appendiculatum.

3b. Calyx without appendages Water-leaf, Hydrophyllum virginicum.

BORAGINACEAE, the Borage Family

Herbs with alternate entire leaves; sepals 5; petals 5, united, corolla generally regular; stamens 5, attached to the corolla-tube; ovary deeply 4-lobed with a single style.

1a. Corolla reddish-purple, about 8 mm. wide (4-10 dm. high; spring) Hound's Tongue, Cynoglossum officinale.

1b. Corolla blue with a yellow center, 4-8 mm. wide (1-5 dm. high; spring and early summer) (Forget-me-not) — 13.

1c. Corolla deep orange, salver-form (2-6 dm. high; spring) (Puccoon) — 15.

1d. Corolla white or blue, or lightly tinged with yellow or red — 2.

2a. Corolla rotate, with a very short tube, bright-blue, about 20 mm. broad (3-8 dm. high; summer) Borage, Borago officinalis.

2b. Corolla tubular, funnel-form, or salver-form — 3.

3a. Corolla 10 mm. long or more; its tube distinctly longer than the calyx — 4.

3b. Corolla less than 10 mm. long; its tube equaling or shorter than the calyx — 8.

4a. Flowers yellowish-white, or somewhat tinged with pink or greenish — 5.

4b. Flowers blue or purple — 6.

5a. Corolla-lobes erect; leaves sessile (3-8 dm. high; early summer) False Gromwell; Onosmodium occidentale.

5b. Corolla-lobes spreading; leaves decurrent (6-10 dm. high; summer) Comfrey, Symphytum officinale.

6a. Stem and leaves glabrous (3-6 dm. high; spring) Bluebell, Mertensia virginica.

6b. Stem and leaves pubescent (4-8 dm. high) — 7.

7a. Corolla regular; leaves ovate or ovate-lanceolate (summer) Bluebell, Mertensia paniculata.

7b. Corolla irregular; leaves linear-oblong (summer) Blueweed, Echium vulgare.

8a. Ovary and fruit covered with hooked prickles — 9.

8b. Ovary and fruit not prickly — 12.

9a. Principal leaves 2.5 cm. wide or more — 10.

9b. Principal leaves 2 cm. wide or less (3-8 dm. high; flowers blue or white, summer) (Stickseed) — 11.

10a. Leaves chiefly basal, the racemes on long leafless peduncles (4-8 dm. high; flowers pale blue, early summer) Wild Comfrey, Cynoglossum boreale.

10b. Stems leafy (8-12 dm. high; flowers white, summer) Beggar Lice, Lappula virginiana.

11a. A bract at the base of each flower Stickseed, Lappula echinata.

11b. Racemes without bracts at the base of each flower Stickseed, Lappula deflexa var. americana.

12a. Racemes bractless, or bracted only at the base (1-4 dm. high) — 14.

12b. Raceme with a bract at the base of each flower (flowers white or yellowish) — 17.

13a. Corolla 4 mm. wide Forget-me-not, Myosotis laxa.

13b. Corolla 6-8 mm. wide Forget-me-not, Myosotis scorpioides.

14a. Calyx-lobes all of equal length (summer) Scorpion Grass, Myosotis arvensis.

14b. Calyx-lobes distinctly unequal in length (spring) Scorpion Grass, Myosotis virginica.

15a. Corolla-lobes denticulate Puccoon, Lithospermum angustifolium.

15b. Corolla-lobes entire — 16.

16a. Flowers sessile; stem softly pubescent Puccoon, Lithospermum canescens.

16b. Flowers on pedicels 2-5 mm. long; stem hispid or bristly Puccoon, Lithospermum gmelini.

17a. Corolla white; fruit brown and wrinkled (weed 2-4 dm. high; spring and summer) Corn Gromwell, Lithospermum arvense.

17b. Corolla yellowish-white; fruit white and smooth (5-10 dm. high) — 18.

18a. Corolla distinctly surpassing the calyx in length (spring and summer) Corn Gromwell, Lithospermum officinale.

18b. Corolla equaling or shorter than the calyx (spring) Wild Gromwell, Lithospermum latifolium.

LABIATAE, the Mint Family

Herbs with opposite leaves, square stems, and usually aromatic odor; flowers irregular, with united petals, or almost regular; stamens 2 or 4, attached to the tube of the corolla; ovary deeply 4-lobed, with a single style.

1a. Stamens 2 — 2.

1b. Stamens 4 — 15.

2a. Corolla regular or nearly so; flowers white, in dense axillary clusters; plants usually of wet grounds (2-8 dm. high; summer and autumn) — 3.

2b. Corolla distinctly irregular and more or less 2-lipped — 7.

3a. Calyx-teeth short, triangular, acute or obtuse (Bugle Weed) — 4.

3b. Calyx-teeth narrow, acuminate or cuspidate (Water Hoarhound) — 5.

4a. Stems and stolons bearing tubers Bugle Weed, Lycopus uniflorus.

4b. Stems and stolons not bearing tubers Bugle Weed, Lycopus virginicus.

5a. Leaves serrate; calyx-teeth sharp-pointed — 6.

5b. Leaves coarsely incised; calyx-teeth awn-tipped Water Hoarhound, Lycopus americanus.

6a. Corolla twice as long as the calyx; leaves narrowed at the base Water Hoarhound, Lycopus rubellus.

6b. Corolla barely longer than the calyx; leaves sessile or nearly so Water Hoarhound, Lycopus lucidus var. americanus.

7a. Corolla blue, 3-4 mm. long; flowers in loose axillary clusters (1-4 dm. high; summer) (Pennyroyal) — 8.

7b. Corolla 8-40 mm. long — 9.

8a. Leaves serrate Pennyroyal, Hedeoma pulegioides.

8b. Leaves linear, entire Pennyroyal, Hedeoma hispida.

9a. Lower lobe of the corolla fringed, very much longer than the upper (5-15 dm. high; corolla pale-yellow; late summer) Horse Balm, Collinsonia canadensis.

9b. Lower lobe of the corolla nearly or quite as long as the upper and not fringed — 10.

10a. Calyx narrowly tubular; its teeth about equal in size (5-10 dm. high; flowers in dense terminal heads, in summer) — 11.

10b. Calyx campanulate, 2 of its teeth different in size from the other 3 (4-8 dm. high; flowers pink-purple, in terminal clusters in summer) — 14.

11a. Corolla scarlet Oswego Tea, Monarda didyma.

11b. Corolla bright crimson or rose-red Wild Bergamot, Monarda fistulosa var. rubra.

11c. Corolla white, pink, pale-purple, or yellowish — 12.

12a. Flower-clusters all terminal — 13.

12b. Flower-clusters both terminal and axillary Horse Mint, Monarda punctata.

13a. Leaves and stem with soft spreading pubescence Wild Bergamot, Monarda fistulosa.

13b. Leaves and stem grayish with fine appressed pubescence Wild Bergamot, Monarda mollis.

14a. Upper calyx-teeth about 3 times as long as the lower Blephilia, Blephilia hirsuta.

14b. Upper calyx-teeth but little longer than the lower Blephilia, Blephilia ciliata.

15a. Calyx with a distinct protuberance on the back of the upper side (Skullcap) — 16.

15b. Calyx without a distinct protuberance — 20.

16a. Corolla 5-8 mm. long; flowers in axillary racemes (3-8 dm. high; flowers blue, in summer) Mad-dog Skullcap, Scutellaria lateriflora.

16b. Corolla 6-10 mm. long; flowers axillary, solitary (1-3 dm. high; flowers violet, early summer) Skullcap, Scutellaria parvula.

16c. Corolla 12-30 mm. long; flowers axillary or in terminal racemes (4-8 dm. high; flowers blue, summer) — 17.

17a. Stem-leaves cordate Skullcap, Scutellaria versicolor.

17b. Stem-leaves not distinctly cordate — 18.

18a. Stem-leaves sessile or nearly so; plant of swamps and river-banks Skullcap, Scutellaria galericulata.

18b. Stem-leaves with petioles 1 cm. or more long; plants of dry or moist woods — 19.

19a. Stem glandular-pubescent toward the summit; corolla 16 mm. long or less Skullcap, Scutellaria pilosa.

19b. Stem not glandular; corolla 20 mm. long Skullcap, Scutellaria incana.

20a. Calyx-teeth 5, all equal or nearly so at the time of flowering — 28.

20b. Calyx-teeth 5, one of them different in size and shape from the other four (2-6 dm. high; flowers light blue, summer) Dragon Head, Dracocephalum parviflorum.

20c. Calyx-teeth 5, two of them different in size and shape from the other three — 21.

20d. Calyx-teeth 10, subulate (woolly plant 4-10 dm. high, with whitish flowers in axillary clusters in summer) Hoarhound, Marrubium vulgare.

21a. Corolla deeply split on the upper side and the stamens protruding; upper lip of the calyx much shorter than the lower (5-10 dm. high; flowers pink-purple, in terminal spikes, summer) (Wood Sage) — 22.

21b. Corolla not deeply split on the upper side — 23.

22a. Calyx canescent Wood Sage, Teucrium canadense.

22b. Calyx villous Wood Sage, Teucrium occidentale.

23a. Flowers in dense terminal head-like spikes, none axillary (1-5 dm. high; flowers pink-purple or blue, in summer) Self-heal, Prunella vulgaris.

23b. Some or all of the flowers in axillary clusters — 24.

24a. Leaves linear, entire (1-4 dm. high; flowers purple, summer) — 25.

24b. Leaves oblong to ovate (summer) — 26.

25a. Pedicels shorter than the calyx Summer Savory, Satureja hortensis.

25b. Pedicels much longer than the calyx Calamint, Satureja glabra.

26a. Leaves 1 cm. long or less, entire (stems growing in mats, 1-3 dm. long; flowers purple, in summer) Wild Thyme, Thymus serpyllum.

26b. Leaves dentate (flowers purple, summer) — 27.

27a. Flowers subtended by bracts as long as the calyx (2-5 dm. high) Basil, Satureja vulgaris.

27b. Flowers with minute bracts or none (1-3 dm. high) Basil-thyme, Satureja acinos.

28a. Corolla 2-lipped or nearly regular, the upper lip flattened, not conspicuously arched over the stamens — 29.

28b. Corolla conspicuously 2-lipped, the stamens ascending under the concave upper lip — 42.

29a. Flowers in dense terminal spikes; corolla 2-lipped (8-15 dm. high; summer) — 30.

29b. Flowers peduncled, 1-4 in the axils of linear leaves — 25b.

29c. Flowers in many-flowered whorls, which are axillary or terminal, or aggregated into terminal spikes or racemes — 31.

30a. Corolla yellowish Giant Hyssop, Agastache nepetoides.

30b. Corolla purplish Giant Hyssop, Agastache scrophulariaefolius.

31a. Corolla distinctly irregular, the lower lip longer than the upper — 32.

31b. Corolla almost regular, the lobes nearly uniform in size — 35.

32a. Stem-leaves sessile or very nearly so (flowers blue) — 33.

32b. Stem-leaves long-petioled — 34.

33a. Leaves linear-oblong, acute at both ends (3-8 dm. high; summer) Hyssop, Hyssopus officinalis.

33b. Leaves oblong to ovate, rounded at the ends (2-4 dm. high; late spring) Bugle, Ajuga reptans.

34a. Leaves ovate to oblong, acute; flowers pink, white, or pale purple (6-15 dm. high; summer) Catnip, Nepeta cataria.

34b. Leaves nearly circular or kidney-shape; flowers blue (creeping; flowers in spring and summer) Ground Ivy, Nepeta hederacea.

35a. Flowers in terminal spikes, or the lower axillary (3-8 dm. high; flowers pink-purple or white, summer) (Mint) — 36.

35b. Flowers all in axillary whorls (flowers pink-purple or white, summer) (Mint) — 38.

35c. Flowers in terminal capitate corymbed clusters (4-8 dm. high; flowers white or dotted with purple, summer) (Mountain Mint) — 41.

36a. Leaves sessile or with very short petiole Spearmint, Mentha spicata.

36b. Leaves with manifest petioles — 37.

37a. Principal leaves less than half as broad as long Peppermint, Mentha piperita.

37b. Principal leaves more than half as broad as long Bergamot Mint, Mentha citrata.

38a. Stem glabrous; leaves ovate to obovate (4-8 dm. high) Downy Mint, Mentha gentilis.

38b. Stem pubescent, at least on the angles (1-6 dm. high) — 39.

39a. Principal leaves distinctly petioled and somewhat rounded at base Wild Mint, Mentha arvensis.

39b. Leaves tapering to the base — 40.

40a. Leaves and stem pubescent Wild Mint, Mentha arvensis var. canadensis.

40b. Leaves glabrous; stem pubescent on the angles only Wild Mint, Mentha arvensis var. glabrata.

41a. Leaves linear; calyx-teeth awl-shape Mountain Mint, Pycnanthemum flexuosum.

41b. Leaves narrowly lanceolate; calyx-teeth triangular-ovate Mountain Mint, Pycnanthemum virginianum.

42a. Stems decumbent to diffuse; leaves cordate to nearly circular (stems 2-5 dm. long or high; flowers in spring and summer) (Dead Nettle) — 43.

42b. Stem erect; leaves palmately cleft; calyx-teeth spiny (6-15 dm. tall; flowers pink, in summer) Motherwort, Leonurus cardiaca.

42c. Stems erect or ascending; leaves ovate-lanceolate to linear (summer) — 45.

43a. Upper leaves closely sessile (flowers red-purple) Dead Nettle, Lamium amplexicaule.

43b. Leaves all petioled — 44.

44a. Flowers red or purple Dead Nettle, Lamium maculatum.

44b. Flowers white Dead Nettle, Lamium album.

45a. Flowers 2-2.5 cm. long, in loose terminal spikes (5-10 dm. tall; flowers rose-color) False Dragon Head, Physostegia virginiana.

45b. Flowers 1-2 cm. long, in axillary and terminal spiked whorls — 46.

46a. Calyx-teeth spiny pointed (flowers pink or pale-purple) (Hemp Nettle) — 47.

46b. Calyx-teeth acute to awl-shape, but not spiny (3-10 dm. high; flowers pale-purple) (Hedge Nettle) — 48.

47a. Leaves ovate (3-8 dm. high) Hemp Nettle, Galeopsis tetrahit.

47b. Leaves linear to lanceolate (1-4 dm. high) Hemp Nettle, Galeopsis ladanum.

48a. Leaves glabrous — 49.

48b. Leaves distinctly pubescent — 50.

49a. Leaves ovate-lanceolate, serrate Hedge Nettle, Stachys tenuifolia.

49b. Leaves linear-oblong, entire or nearly so Hedge Nettle, Stachys hyssopifolia.

50a. Stem pubescent on the angles alone; leaves petioled Hedge Nettle, Stachys tenuifolia var. aspera.

50b. Stem pubescent on both sides and angles; leaves nearly sessile — 51.

51a. Leaves oblong or oblong-lanceolate, more than 1 cm. wide Hedge Nettle, Stachys palustris.

51b. Leaves linear-lanceolate, 1 cm. wide or less Hedge Nettle, Stachys arenicola.

VERBENACEAE, the Verbena Family

Herbs, with simple opposite leaves and slightly irregular flowers in spikes or heads; petals 5, united and bearing the 4 stamens in the corolla-tube; ovary 1, 2-celled or 4-celled, with 1 style.

1a. Plants prostrate or spreading — 2.

1b. Plants erect (flowers in summer) (Vervain) — 3.

2a. Leaves serrate; flowers in short dense spikes (flowers pale-blue, summer) Fog Fruit, Lippia lanceolata.

2b. Leaves pinnatifid; flowers in loose bracted spikes (flowers light-purple, summer) Vervain, Verbena bracteosa.

3a. Spikes dense, continuous (flowers purple or blue, varying to white) — 4.

3b. Spikes slender, interrupted, the flowers scattered (corolla white or pale-blue) — 6.

4a. Leaves lanceolate, manifestly petioled (1-2 m. high) Vervain, Verbena hastata.

4b. Leaves sessile, not lanceolate (5-8 dm. high) — 5.

5a. Leaves narrowly oblanceolate, tapering at the entire base Vervain, Verbena angustifolia.

5b. Leaves oblong to obovate, not tapering at the base Vervain, Verbena stricta.

6a. Leaves incised, tapering to a sessile base (5-10 dm. high) Vervain, Verbena, officinalis.

6b. Leaves serrate, petioled (1-2 m. high) Vervain, Verbena urticaefolia.

SOLANACEAE, the Nightshade Family

Herbs or shrubs, with alternate leaves and regular or slightly irregular flowers; sepals 5, united; corolla of 5 united petals, bearing the 5 stamens attached; ovary 1, 2-5 (usually 2)-celled, with a slender style.

1a. Corolla rotate; anthers close together (flowers in summer) — 2.

1b. Corolla not rotate; anthers separate — 5.

2a. Stem and leaves prickly (3-8 dm. high) — 3.

2b. Stem and leaves not prickly — 4.

3a. Flowers white or bluish Horse Nettle, Solanum carolinense.

3b. Flowers yellow Buffalo Bur, Solanum rostratum.

4a. Climbing vine; leaves frequently lobed (flowers blue) Bittersweet, Solanum dulcamara.

4b. Not climbing; leaves toothed (flowers white) Nightshade, Solanum nigrum.

5a. Climbing or trailing shrub, with purplish, white, or greenish flowers about 1 cm. wide (frequently thorny; flowers in summer) Matrimony Vine, Lycium halimifolium.

5b. Herbaceous plants, not climbing — 6.

6a. Flowers white, red, or blue, 2.5 cm. or more wide (summer) — 7.

6b. Flowers yellow, yellowish-white, or greenish-yellow (summer) — 12.

7a. Corolla-tube 10 cm. long or more (5-12 dm. high) — 8.

7b. Corolla-tube 5 cm. long or less — 10.

8a. Stem finely pubescent; leaves entire or nearly so Thorn-apple, Datura metel.

8b. Stem glabrous; leaves coarsely toothed (Jimson Weed) — 9.

9a. Stem green; corolla white Jimson Weed, Datura stramonium.

9b. Stem purple; corolla light-blue or purple Jimson Weed, Datura tatula.

10a. Corolla pale-blue (5-10 dm. high) Apple of Peru, Nicandra physalodes.

10b. Corolla, red or violet (2-4 dm. high) Petunia, Petunia violacea.

10c. Corolla white — 11.

11a. Corolla all white (2-4 dm. high) Petunia, Petunia axillaris.

11b. Corolla with yellow center White Ground Cherry, Physalis grandiflora.

12a. Corolla 30 mm. wide or more, somewhat irregular; stamens declined to one side (3-6 dm. high) Henbane, Hyoscyamus niger.

12b. Corolla smaller, strictly regular — 13.

13a. Flowers in terminal panicles; corolla tubular, with slightly spreading lobes (5-10 dm. high) Wild Tobacco, Nicotiana rustica.

13b. Flowers solitary in the axils; corolla short, widely spreading (3-8 dm. high) (Ground Cherry) — 14.

14a. Annuals with branching slender roots — 15.

14b. Perennials with thickened roots and rootstocks — 16.

15a. Plants pubescent Ground Cherry, Physalis pubescens.

15b. Plants smooth, or with a few scattered hairs Ground Cherry, Physalis ixocarpa.

16a. Stem viscid-pubescent Ground Cherry, Physalis heterophylla.

16b. Stem glabrous or slightly pubescent, not viscid — 17.

17a. Leaves and stem distinctly pubescent Ground Cherry, Physalis virginiana.

17b. Leaves and stem almost glabrous Ground Cherry, Physalis subglabrata.

SCROPHULARIACEAE, the Figwort Family

Herbs with opposite or alternate leaves and usually irregular flowers; corolla of united petals, bearing the 2 or 4 (or rarely 5) stamens attached; petals actually 5, but sometimes apparently only 2 or 4; a sterile fifth stamen sometimes present; ovary superior, 2-celled.

1a. Anther-bearing stamens 5 (6-15 dm. high; flowers in summer) (Mullein) — 2.

1b. Anther-bearing stamens 4; a sterile fifth stamen may or may not be present — 3.

1c. Anther-bearing stamens 2 — 37.

2a. Leaves densely white-woolly; flowers yellow, in dense spikes Mullein, Verbascum thapsus.

2b. Leaves smooth or nearly so; flowers yellow or white, in loose racemes Moth Mullein, Verbascum blattaria.

3a. Flowers (not the bracts) greenish-yellow, yellow, or orange — 4.

3b. Flowers blue, purple, brown, red, pink, or white, never yellow — 16.

4a. Flowers in dense terminal leafy-bracted spikes — 5.

4b. Flowers in loose racemes or axillary — 9.

5a. Corolla 7 mm. long or less, or none — 6.

5b. Corolla 12 mm. long or more — 7.

6a. Leaves alternate (3-6 dm. high; early summer) Synthyris, Synthyris bullii.

6b. Leaves opposite (1-2 dm. high; summer) Eyebright, Euphrasia arctica.

7a. Stem-leaves entire (2-6 dm. high; summer) Painted Cup, Castilleja pallida var. septentrionalis.

7b. Stem-leaves palmately lobed, bracteal leaves scarlet (3-6 dm. high; early summer) Painted Cup, Castilleja coccinea.

7c. Stem-leaves pinnately lobed or incised (Lousewort) — 8.

8a. Flowers in spring (2-4 dm. high) Lousewort, Pedicularis canadensis.

8b. Flowers in late summer (3-8 dm. high) Lousewort, Pedicularis lanceolata.

9a. Upper lip of the corolla very different in size and shape from the lower lip — 10.

9b. Upper lip of the corolla resembling the lower lip in shape, and not very different in size (5-12 dm. high; summer) (False Foxglove) — 13.

10a. Leaves alternate (2-5 dm. high; summer) Butter-and-eggs, Linaria vulgaris.

10b. Leaves opposite — 11.

11a. Stem erect; leaves narrowed at the base — 30b.

11b. Stem creeping or spreading (summer) — 12.

12a. Leaves pinnately veined, ovate Musk Flower, Mimulus moschatus.

12b. Leaves palmately veined, circular or nearly so Yellow Monkey Flower, Mimulus glabratus var. jamesii.

13a. Stem glabrous — 14.

13b. Stem pubescent — 15.

14a. Principal stem-leaves pinnatifid False Foxglove, Gerardia virginica.

14b. Principal stem-leaves entire False Foxglove, Gerardia laevigata.

15a. Corolla hairy on the outside False Foxglove, Gerardia pedicularia.

15b. Corolla smooth on the outside False Foxglove, Gerardia flava.

16a. Leaves all basal; flowers on leafless stalks (1 dm. high or less; flowers pink or white, summer) Mudwort, Limosella aquatica var. tenuifolia.

16b. Leaves opposite (those subtending the flowers may be alternate) — 20.

16c. Leaves alternate or irregularly scattered — 17.

17a. Leaves entire — 18.

17b. Leaves pinnately lobed or incised — 8a.

17c. Leaves palmately veined and lobed; stem trailing (flowers blue, summer) Kenilworth Ivy, Linaria cymbalaria.

18a. Corolla-tube less than 1 cm. long, spurred — 19.

18b. Corolla more than 2 cm. long, not spurred (3-8 dm. high; flowers red-purple, summer) Snapdragon, Antirrhinum majus.

19a. Stem and foliage pubescent (1-3 dm. high; flowers blue, summer) Small Snapdragon, Linaria minor.

19b. Stem and foliage glabrous (2-6 dm. high; flowers blue, summer) Toad-flax, Linaria canadensis.

20a. Leaves with 1 or 2 lobes near the base (3-5 dm. high; flowers purple, summer) Gerardia, Gerardia auriculata.

20b. Leaves linear (2-6 dm. high; flowers rose-purple, summer and autumn) (Gerardia) — 21.

20c. Leaves lanceolate or broader, not lobed — 26.

21a. Pedicels equaling or but little longer than the calyx, and conspicuously shorter than the subtending leaf — 22.

21b. Pedicels much longer than the calyx, and generally equaling or exceeding the subtending leaf — 24.

22a. Plants of moist ground, bogs, and shores — 23.

22b. Plants of dry uplands Gerardia, Gerardia aspera.

23a. Corolla about 25 mm. long Gerardia, Gerardia purpurea.

23b. Corolla less than 20 mm. long Gerardia, Gerardia paupercula.

24a. Stem rough on the angles — 25.

24b. Stem glabrous Gerardia, Gerardia tenuifolia.

25a. Leaves 2-5 mm. wide Gerardia, Gerardia tenuifolia var. macrophylla.

25b. Leaves thread-like, 1 mm. wide or less Gerardia, Gerardia skinneriana.

26a. Corolla 16 mm. long, or shorter — 27.

26b. Corolla 20 mm. long, or longer — 32.

27a. Corolla dull-purple, brown, or greenish; one sterile stamen present (1-2.5 m. high; flowers in summer) (Figwort) — 28.

27b. Corolla blue or white (1-4 dm. high) — 29.

28a. Sterile stamen purple Figwort, Scrophularia marilandica.

28b. Sterile stamen yellow Figwort, Scrophularia leporella.

29a. Flowers nearly or quite sessile (summer) — 30.

29b. Flowers on pedicels 10 mm. long or more (spring) — 31.

30a. Foliage-leaves prominently toothed — 6b.

30b. Foliage-leaves entire, or with 1 or 2 small teeth at the base Cow Wheat, Melampyrum lineare.

31a. Corolla more than 10 mm. long, blue and white Blue-eyed Mary, Collinsia verna.

31b. Corolla 5-8 mm. long, blue and white Collinsia, Collinsia parviflora.

32a. Flowers solitary in the axils of the upper foliage-leaves (4-8 dm. high; flowers blue, in summer) (Monkey Flower) — 33.

32b. Flowers in dense terminal or subterminal spikes (3-9 dm. high; summer) — 34.

32c. Flowers in loose terminal panicles (flowers white or pale-violet) (Beard-tongue) — 35.

33a. Leaves clasping at the base Monkey Flower, Mimulus ringens.

33b. Leaves petioled, not clasping Monkey Flower, Mimulus alatus.

34a. Stem and foliage glabrous (flowers white) Turtlehead, Chelone glabra.

34b. Stem and foliage pubescent (flowers purple) Blue Hearts, Buchnera americana.

35a. Stem finely pubescent (3-6 dm. high; flowers pale-violet, late spring) Beard-tongue, Pentstemon hirsutus.

35b. Stem glabrous below the inflorescence (6-12 dm. high) — 36.

36a. Corolla-tube gradually enlarged from base to tip (flowers pale-violet, in early summer) Beard-tongue, Pentstemon laevigatus.

36b. Corolla-tube abruptly enlarged just beyond the calyx (flowers white, early summer) Beard-tongue, Pentstemon laevigatus var. digitalis.

37a. Corolla distinctly irregular, 2-lipped (1-4 dm. high; flowers yellowish or white, summer) — 38.

37b. Corolla regular or nearly so and 2-lobed, or none — 6a.

37c. Corolla regular or nearly so, 4-lobed — 40.

38a. Leaves narrowed at the base, with mid-vein Hedge Hyssop, Gratiola virginiana.

38b. Leaves rounded or somewhat clasping at the base, with 3-5 principal veins (False Pimpernel) — 39.

39a. Peduncles longer than the subtending leaves False Pimpernel, Ilysanthes anagallidea.

39b. Peduncles shorter than the subtending leaves False Pimpernel, Ilysanthes dubia.