CAPPARIDACEAE, the Caper Family

Herbs, with alternate compound leaves, 4 petals, and 6 or more stamens, which are about equal in length; fruit a 1-celled pod.

One species in Michigan, stamens about 11; leaflets 3 (2-4 dm. high; flowers yellowish, in summer) Clammy-weed, Polanisia graveolens.


RESEDACEAE, the Mignonette Family

Herbs, with alternate leaves and terminal racemes of small yellowish flowers; sepals 6, petals 6, stamens numerous.

One species in Michigan, with divided leaves and irregularly cleft petals, blooming in summer Yellow Mignonette, Reseda lutea.


SARRACENIACEAE, the Pitcher Plant Family

Insectivorous plants, with hollow, pitcher-shaped leaves, and large purple flowers at the ends of naked stems.

One species in Michigan, growing in bogs and blooming in late spring Pitcher Plant, Sarracenia purpurea.


DROSERACEAE, the Sundew Family

Insectivorous herbs, with a rosette of basal leaves bearing gland-tipped bristles on their upper surface, and with slender racemes of small white flowers in summer; inhabitants of bogs and swamps (2 dm. high, or less).

1a. Leaf-blade about as long as wide Sundew, Drosera rotundifolia.
1b. Leaf-blade about 2-3 times as long as wide Sundew, Drosera longifolia.
1c. Leaf-blade about 5-8 times as long as wide Sundew, Drosera anglica.
1d. Leaf-blade narrowly linear, about 10 times as long as wide Sundew, Drosera linearis.


PODOSTEMACEAE, the River Weed Family

Small submerged aquatics, growing attached to stones in running water, with dissected leaves and minute flowers.

One species in Michigan River Weed, Podostemum ceratophyllum.


CRASSULACEAE, the Orpine Family

Herbs, with usually alternate leaves; the sepals, petals, and pistils each 4 or 5, or in one species the petals none, and the stamens as many or twice as many as the sepals.

1a. Leaves entire (Stonecrop) — 2.
1b. Leaves toothed — 3.
2a. Leaves 3-5 mm. long, very thick and fleshy (tufted plants about 1 dm. high, with yellow flowers in summer) Stonecrop, Sedum acre.
2b. Leaves 10-30 mm. long, flat (tufted plants 1-2 dm. high; flowers white, in spring) Stonecrop, Sedum ternatum.
3a. Petals present, purple (2-5 dm. high; summer) Live-for-ever, Sedum purpureum.
3b. Petals none (3-6 dm. high; summer) Ditch Stonecrop, Penthorum sedoides.


SAXIFRAGACEAE, the Saxifrage Family

Herbs or shrubs, with alternate or opposite leaves; petals and sepals each 5, or the petals none; stamens 5 or 10; styles or stigmas 2-4.

1a. Shrubs with lobed leaves (3-15 dm. high; flowers in late spring) — 2.
1b. Herbs — 12.
2a. Stems thorny — 3.
2b. Stems not thorny (Currant) — 8.
3a. Flowers and fruits in racemes Swamp Currant, Ribes lacustre.
3b. Flowers and fruit in short clusters (Gooseberry) — 4.
4a. Ovary and fruit prickly and bristly Gooseberry, Ribes cynosbati.
4b. Ovary and fruit smooth, or sometimes a little glandular — 5.
5a. Stamens equaling the ovate calyx-lobes in length, or a very little longer — 6.
5b. Stamens distinctly longer than the linear calyx-lobes — 7.
6a. Leaves glabrous beneath, or nearly so Gooseberry, Ribes oxyacanthoides.
6b. Leaves softly pubescent beneath Gooseberry, Ribes oxyacanthoides var. calcicola.
7a. Flowers, including the stamens, about 15 mm. long Gooseberry, Ribes gracile.
7b. Flowers, including the stamens, about 8 mm. long Gooseberry, Ribes rotundifolium.
8a. Calyx prolonged above the ovary into a tube which is longer than the sepals — 9.
8b. Calyx-tube shorter than the ovary or none — 10.
9a. Flowers greenish-yellow, inconspicuous; calyx-tube narrowly bell-shape Black Currant, Ribes floridum.
9b. Flowers bright yellow, conspicuous; calyx-tube narrow, with spreading lobes Golden Currant, Ribes aureum.
10a. Ovary and berry bristly with glandular hairs Skunk Currant, Ribes prostratum.
10b. Ovary and fruit smooth, or with sessile glands — 11.
11a. Leaves dotted beneath with resinous glands Black Currant, Ribes hudsonianum.
11b. Leaves glabrous or pubescent beneath, without resinous glands Red Currant, Ribes triste.
12a. Flowers minute, yellowish, without petals, in the axils of the leaves (1-2 dm. high; flowers in spring) Golden Saxifrage, Chrysosplenium americanum.
12b. Flowers large, solitary, terminating erect stalks (leaves mostly basal; flowers white, in late summer; flower-stalks 1-5 dm. high) (Grass-of-Parnassus) — 13.
12c. Flowers in terminal racemes, panicles, or clusters — 15.
13a. Flowers less than 2 cm. wide; leaves narrowed to the base Grass-of-Parnassus, Parnassia parviflora.
13b. Flowers 2-3.5 cm. wide; leaves rounded or cordate at the base — 14.
14a. A 3-cleft scale at the base of each petal Grass-of-Parnassus, Parnassia caroliniana.
14b. A many-cleft (9-15) scale at the base of each petal Grass-of-Parnassus, Parnassia palustris.
15a. Leaves linear to oblanceolate, 3 times as long as broad, or more, and pinnately veined (Saxifrage) — 16.
15b. Leaves broadly ovate to nearly circular, frequently cordate at the base, and always palmately veined or lobed — 20.
16a. Leaves basal; the flower-stalk bearing no leaves except small ones at the base of its branches — 17.
16b. Flower-stalk leafy below (1-3 dm. high; flowers yellow, summer) — 18.
17a. Petals white; sepals erect; leaves conspicuously toothed, 3-10 cm. long (1-3 dm. high; spring) Saxifrage, Saxifraga virginiensis.
17b. Petals greenish; sepals reflexed; leaves minutely toothed or entire, 10-30 cm. long (5-10 dm. high; spring) Saxifrage, Saxifraga pennsylvanica.
18a. Leaves with 3 sharp teeth at the apex Saxifrage, Saxifraga tricuspidata.
18b. Leaves with numerous teeth or entire — 19.
19a. Leaves linear, chiefly on the stem Saxifrage, Saxifraga aizoides.
19b. Leaves spatulate, chiefly in a basal rosette Saxifrage, Saxifraga aizoon.
20a. Stamens 5 (leaves mostly basal; flowers greenish or purplish in late spring, on stalks 5-10 dm. high) (Alum Root) — 21.
20b. Stamens 10 (flowers white, in spring) — 23.
21a. Flowers regular Alum Root, Heuchera americana.
21b. Flowers irregular, the calyx oblique, longer on the upper side than on the lower — 22.
22a. Stamens projecting beyond the calyx Alum Root, Heuchera hirsuticaulis.
22b. Stamens not projecting beyond the calyx Alum Root, Heuchera hispida.
23a. Stem-leaves alternate or none — 24.
23b. Stem with a pair of opposite leaves (2-4 dm. high) Bishop's Cap, Mitella diphylla.
24a. Petals deeply fringed (1-2 dm. high) Bishop's Cap, Mitella nuda.
24b. Petals entire (1-3 dm. high) False Mitrewort, Tiarella cordifolia.


HAMAMELIDACEAE, the Witch Hazel Family

Shrubs, with alternate simple leaves; sepals, petals, and stamens each 4; ovary 2-lobed.

One species in Michigan; tall shrub with obovate leaves and yellow flowers appearing late in autumn Witch Hazel, Hamamelis virginiana.


PLATANACEAE, the Plane Tree Family

Trees, with broad, palmately veined and lobed leaves, and minute flowers in dense spherical heads.

One species in Michigan Sycamore, Platanus occidentalis.


ROSACEAE, the Rose Family

Trees, herbs, or shrubs, with alternate, frequently compound leaves; petals and sepals usually 5, stamens numerous, pistils 1 to many; receptacle expanded into a saucer-shape or cup-shape organ, bearing the sepals, petals, and stamens at its margin, the pistils at its center, and resembling a calyx-tube or flattened calyx.

1a. Shrubs or trees — 2.
1b. Herbaceous plants — 48.
2a. Leaves compound — 3.
2b. Leaves simple — 24.
3a. Flowers in large panicles or corymbs, each flower 5-10 mm. across; leaflets 7 or more — 4.
3b. Flowers solitary or in small clusters, each flower usually 20-80 mm. wide; leaflets frequently only 3 or 5 — 7.
4a. Flowers in a pyramidal or oblong panicle, the ovaries superior (1-2 m. high; flowers white, in summer) — 70b.
4b. Flowers in rounded or hemispheric clusters, the ovary inferior — 5.
5a. Leaves pubescent on the lower surface Rowan Tree, Pyrus aucuparia.
5b. Leaves glabrous beneath when mature (small trees; flowers white, in early summer or late spring) (Mountain Ash) — 6.
6a. Leaves acuminate at the apex Mountain Ash, Pyrus americana.
6b. Leaves obtuse or acute at the apex Mountain Ash, Pyrus sitchensis.
7a. Flowers yellow (5-10 dm. high; summer) Cinquefoil, Potentilla fruticosa.
7b. Flowers pink or red, rarely white, 4-10 cm. across (shrubs, 5-15 dm. high, or climbing; stems usually thorny; flowers in early summer) (Rose) — 8.
7c. Flowers white, 1-3 cm. across (4-20 dm. high; flowers in late spring) — 16.
8a. Leaflets on most of the leaves 3; styles cohering in a column which protrudes from among the stamens Climbing Rose, Rosa setigera.
8b. Leaflets 5-11; styles not cohering in a protruding column — 9.
9a. Sepals persistent on the fruit after flowering — 10.
9b. Sepals soon deciduous from the young fruit after flowering — 14.
10a. A pair of spines below each leaf larger than the other spines — 11.
10b. Spines all alike in size or nearly so, or absent completely — 12.
11a. Sepals entire Wild Rose, Rosa woodsii.
11b. Sepals pinnatifid Dog Rose, Rosa canina.
12a. Stems with few thorns or none at all Wild Rose, Rosa blanda.
12b. Stems prickly — 13.
13a. Fruit somewhat pear-shape, narrowed toward the base. Wild Rose, Rosa acicularis.
13b. Fruit globose, rounded at the base Wild Rose, Rosa acicularis var. bourgeauiana.
14a. The pair of spines at the base of each leaf straight or nearly so Wild Rose, Rosa humilis.
14b. The pair of spines at the base of each leaf distinctly recurved or hooked — 15.
15a. Leaves densely glandular-pubescent beneath Sweetbrier, Rosa rubiginosa.
15b. Leaves glabrous or minutely pubescent Swamp Rose, Rosa carolina.
16a. Stems trailing or creeping — 17.
16b. Stems erect, ascending, or arched — 19.
17a. Stems distinctly shrubby and thorny (Dewberry) — 18.
17b. Stems almost herbaceous, without thorns Dwarf Raspberry, Rubus triflorus.
18a. Leaves thin, dull above; fruit black, large and juicy Dewberry, Rubus villosus.
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.