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. |