1. D. nudiflòrum, DC. Leaves all crowded at the summit of sterile stems; leaflets broadly ovate, bluntish, whitish beneath; raceme elongated on an ascending mostly leafless stalk or scape from the root, 2° long.—Dry woods, common.
2. D. acuminàtum, DC. Leaves all crowded at the summit of the stem from which arises the elongated naked raceme or panicle; leaflets round-ovate, taper-pointed, green both sides, the end one round (4–5´ long).—Rich woods, from Canada to the Gulf.
3. D. pauciflòrum, DC. Leaves scattered along the low (8–15´ high) ascending stems; leaflets rhombic-ovate, bluntish, pale beneath; raceme few-flowered, terminal.—Woods, Ont. to Penn., Mich., Kan., and southward.
§ 2. Pod raised on a stalk (stipe) little if at all surpassing the deeply deft calyx; stems long and prostrate or decumbent; racemes axillary and terminal.
[*] Stipules conspicuous, ovate, attenuate, striate, persistent; racemes mostly simple.
4. D. rotundifòlium, DC. Soft-hairy all over, truly prostrate; leaflets orbicular, or the odd one slightly rhomboid; flowers purple; pods almost equally sinuate on both edges, 3–5-jointed; the joints rhomboid-oval.—Dry rocky woods, N. Eng. to Fla., west to Minn., Mo., and La.
Var. glabràtum, Gray, is almost glabrous, otherwise nearly as the ordinary form.—Mass. and N. Y.
5. D. ochroleùcum, M. A. Curtis. Stems sparsely hairy, decumbent; leaflets nearly glabrous, ovate, acute or obtuse, transversely reticulated beneath, the lateral ones smaller or sometimes wanting; racemes much elongated; corolla whitish; pods twisted, 2–4-jointed, the large rhomboid joints smooth and reticulated but the margins downy.—Woodlands, Md. and Va.
[*][*] Stipules smaller, lanceolate and awl-shaped, less persistent; racemes panicled.
6. D. humifùsum, Beck. Glabrous or nearly so, procumbent; leaflets ovate or ovate-oblong, rather obtuse, much smaller than in the two preceding (1¼–2´ long), corolla purple; pods 2–4-jointed, flat, the oval-rhomboid joints minutely scabrous throughout.—Dry sandy soil, S. Penn. to Md.
§ 3. Pod slightly if at all stalked in the calyx; racemes panicled.
[*] Stems tall (3–5°) and erect; the persistent stipules and deciduous bracts large and conspicuous, ovate or ovate-lanceolate, taper-pointed; flowers rather large.
[+] Pods of 4–7 unequal-sided rhombic joints, which are considerably longer than broad (about 6´´ long).
7. D. canéscens, DC. Stem loosely branched, hairy; leaflets ovate, bluntish, about the length of the petioles, whitish and reticulated beneath, both sides roughish with a close fine pubescence; joints of the pod very adhesive.—Moist grounds, Mass. and Vt. to Minn. and southward, chiefly westward. Branches clothed with both minute and hooked, and longer, spreading, rather glutinous hairs.—Var. villosíssimum, Torr. & Gray, has the panicle and upper part of the stem very villous, and leaflets oblong-ovate.—Mo.
8. D. cuspidàtum, Torr. & Gray. Very smooth except the panicle; stem straight; leaflets lanceolate-ovate and taper-pointed, green both sides, longer than the petiole (3–5´); joints of the pod rhomboid-oblong, smoothish.—Thickets, common. The conspicuous bracts and stipules ¾´ long.
[+][+] Pods of 3–5 oval joints (not over 3´´ long).
9. D. Illinoénse, Gray. Erect (3–5° high); stem and leaves with short rough pubescence; leaflets ovate-oblong or ovate-lanceolate (2–4´ long), obtuse, subcoriaceous, cinereous beneath, veins and veinlets prominent, strongly reticulated, the lower leaflets nearly equalling the petiole; pods scarcely over 1´ long, sinuate on both margins (deeper below).—Dry ground, Ill. to Iowa and Kan.
[*][*] Stems (2–5° high) erect; stipules and bracts mostly deciduous, small and inconspicuous; joints of the pod 3–5, triangular or half-rhombic or very unequal-sided rhomboidal, longer than broad, 3´´ or less in length; flowers middle-sized.
10. D. lævigàtum, DC. Smooth or nearly so throughout; stem straight; leaflets ovate, bluntish, pale beneath (2–3´ long); panicles minutely rough-pubescent.—Pine woods, N. J. to Fla., west to Mo. and Tex.
11. D. viridiflòrum, Beck. Stem very downy, rough at the summit; leaflets broadly ovate, very obtuse, rough above, whitened with a soft velvety down underneath (2–3´ long).—Southern N. Y. to N. J. and Fla., west to Mich., Mo., and Tex.
12. D. Dillènii, Darlingt. Stem pubescent; leaflets oblong or oblong-ovate, commonly bluntish, pale beneath, softly and finely pubescent, mostly thin (2–3´ long).—Open woodlands, common.
13. D. paniculàtum, DC. Nearly smooth throughout; stem slender, tall; leaflets oblong-lanceolate, or narrowly lanceolate, tapering to a blunt point, thin (3–5´ long); racemes much panicled.—Copses, common.
14. D. stríctum, DC. Stem very straight and slender, simple (2–3° high), the upper part and narrow panicle rough-glandular; leaflets linear, blunt, strongly reticulated, thickish, very smooth (1–2´ long, ¼´ wide); joints of the pod 1–3, semi-obovate or very gibbous (only 2´´ long).—Pine woods, N. J. to Fla. and La.
[*][*][*] Stipules small and inconspicuous, mostly deciduous; pods of few roundish or obliquely oval or sometimes roundish-rhomboidal joints, 1½–2½´´ long.
[+] Stems erect; bracts before flowering conspicuous; racemes densely flowered.
15. D. Canadénse, DC. Stem hairy (3–6° high); leaflets oblong-lanceolate or ovate-lanceolate, obtuse, with numerous straightish veins, much longer than the petiole (1½–3´ long); flowers showy, larger than in any other species (½–{1/3}´ long).—Dry rich woods, N. Brunswick to N. C., Minn., and Kan.
16. D. sessilifòlium, Torr. & Gray. Stem pubescent (2–4° high); leaves nearly sessile; leaflets linear or linear-oblong, blunt, thickish, reticulated, rough above, downy beneath; branches of the panicle long; flowers small.—Copses, Penn. and Ky., west to Mich., Iowa, Mo., and Tex.
[+][+] Stems ascending (1–3° high); bracts small; racemes or panicles elongated and loosely flowered; flowers small.
17. D. rígidum, DC. Stem branching, somewhat hoary, like the lower surface of the leaves, with a close roughish pubescence; leaflets ovate-oblong, blunt, thickish, reticulated-veiny, rather rough above, the lateral ones longer than the petiole.—Dry hillsides, Mass. to Fla., west to Mich., Mo., and La.
18. D. ciliàre, DC. Stem slender, hairy or rough-pubescent; leaves crowded, on very short hairy petioles; leaflets round-ovate or oval, thickish, more or less hairy on the margins and underneath (½–1´ long).—Dry hills and sandy fields, N. Eng. to Fla., west to Mich., Mo., and Tex.
19. D. Marilándicum, F. Boott. Nearly smooth throughout, slender; leaflets ovate or roundish, very obtuse, thin, the lateral ones about the length of the slender petiole; otherwise resembling the preceding.—Copses, N. Eng. to Fla., west to Mich., Mo., and La.
[+][+][+] Stems reclining or prostrate; racemes loosely flowered.
20. D. lineàtum, DC. Stem minutely pubescent, striate-angled; leaflets orbicular, smoothish (½–1´ long), much longer than the petiole; pod scarcely stalked in the calyx.—Dry soil, Md. and Va. to Fla.