| |
| | 2. Plant armed with prickles, spines, or thorns |
| |
| | 3. Leaves simple, sometimes small or falling early |
| |
| | 4. Plant gland-dotted; corolla blue to pink-purple; seed 1 |
| PSOROTHAMNUS |
| | 4' Plant not gland-dotted; corolla yellow to reddish; seeds few–several |
| |
| | 5. Corolla reddish; fruit narrowed between seeds, glabrous |
| ALHAGI (no key) |
| | 5' Corolla yellow; fruit not narrowed between seeds, hairy |
| ULEX (no key) |
| | 3' Leaves all or mostly compound, generally persistent |
| |
| | 6. Leaf palmately compound; all filaments free |
| PICKERINGIA (no key) |
| | 6' Leaf pinnately compound; all or 9 filaments fused |
| |
| | 7. Plant gland-dotted; fruit indehiscent; seed 1 |
| PSOROTHAMNUS |
| | 7' Plant not gland-dotted; fruit dehiscent (sometimes slowly so); seeds generally several |
| |
| | 8. Leaf odd-pinnate; corolla white or pink — fruit flat |
| ROBINIA |
| | 8' Leaf even-pinnate; corolla not white |
| |
| | 9. Corolla yellow; fruit flat; leaflets 8–12 |
| CARAGANA (no key)2 |
| | 9' Corolla reddish to pink, or 2-colored; fruit plump; leaflets as follows |
| |
| | 10. Leaflets 4; fruit not narrowed between seeds; deciduous shrub |
| HALIMODENDRON (no key) |
| | 10' Leaflets 8–19; fruit generally narrowed between seeds; evergreen shrub or tree |
| OLNEYA (no key) |
| |
| | 11. Petal 1 (the banner) — inflorescence spike-like; fruit indehiscent; seed 1 |
| AMORPHA |
| |
| | 12. Filaments all fused; leaves ternately palmately compound to simple |
| |
| | 13. Leaves tiny, simple; stems generally ± leafless |
| SPARTIUM (no key) |
| | 13' Leaves mostly not tiny, simple or generally compound; stems clearly leafy |
| |
| | 14. Leaf palmately compound, leaflets 5–11; corolla blue, white, or yellow, banner glabrous, keel beaked |
| LUPINUS |
| | 14' Leaf sometimes appearing simple, leaflets 1–3; corolla yellow (or if white then banner hairy), keel obtuse |
| |
| | 15. Calyx cylindric, 8–9 mm; banner white, purple-lined, or spotted, generally hairy |
| CHAMAECYTISUS (no key) |
| | 15' Calyx bell-shaped, < ± 7 mm; banner yellow, generally not hairy |
| |
| | 16. Style generally abruptly curved ± at middle; upper lip of calyx barely 2-lobed |
| CYTISUS |
| | 16' Style ± abruptly bent at tip; upper lip of calyx strongly 2-lobed |
| GENISTA |
| | 12' Filaments all free or 9 fused, 1 (uppermost) free or 0; leaves generally pinnately compound |
| |
| | 17. Leaf even-pinnate; corolla 1.6–2.2 cm, yellow |
| CARAGANA |
| | 17' Leaf odd-pinnate, if clearly neither even nor odd-pinnate (as sometimes in Lotus), corolla < 1.6 cm, yellow or not |
| |
| | 18. Inflorescence generally an umbel, flowers sometimes 1–3; corolla generally yellow |
| LOTUS |
| | 18' Inflorescence a raceme; corolla yellow or not |
| |
| | 19. Corolla generally yellow; fruit large, papery, inflated |
| COLUTEA (no key) |
| | 19' Corolla not yellow; fruit small or large, not papery, not inflated |
| |
| | 20. Flower 15–25 mm; plant not gland-dotted; fruit dehiscent; seeds several |
| ROBINIA |
| | 20' Flower 6–10 mm; plant gland-dotted; fruit indehiscent; seed 1 (see also Marina) |
| PSOROTHAMNUS |
| | 1' Annual, perennial herb, subshrub |
| |
| | 21. Leaflets 0, but stipules leaflet-like — leaf axis ending as a tendril |
| LATHYRUS |
| |
| | 22. Leaf palmately compound; leaflets generally 3–9 |
| |
| | 23. All filaments free; corolla yellow, 15–25 mm |
| THERMOPSIS (no key) |
| | 23' All or 9 filaments fused; corolla not yellow or, if so, generally < 15 mm |
| |
| | 24. Leaflet gland-dotted; fruit indehiscent or breaking transversely; seed 1 |
| |
| | 25. Leaves mostly basal or clustered; leaflets widely obovate to oblanceolate; fruit included in calyx except for conspicuous beak |
| PEDIOMELUM |
| | 25' Leaves cauline; leaflets obovate to linear; fruit exserted from calyx |
| PSORALIDIUM (no key) |
| | 24' Leaflets not gland-dotted; fruit indehiscent or dehiscent through longitudinal sutures; seeds generally several |
| |
| | 26. Filaments of all stamens fused at least in basal 1/2; leaflets generally 5–9, entire |
| LUPINUS |
| | 26' Filaments of 9 stamens fused, the 10th (uppermost) free; leaflets 3–5, entire, or margin toothed or wavy |
| |
| | 27. Leaflets 5, lower 2 in stipular position, others palmate, stipules reduced to bumps or not apparent; inflorescence an umbel, corolla yellow |
| LOTUS |
| | 27' Leaflets generally 3, lower 2 not in stipular position, stipules generally papery or membranous, not reduced to bumps, rarely leaflet-like, if so then inflorescence not an umbel and corolla not yellow |
| |
| | 28. Leaflet entire; fruit not enclosed in corolla |
| ASTRAGALUS |
| | 28' Leaflet margin ± toothed or wavy; fruit enclosed in persistent corolla |
| TRIFOLIUM |
| | 22' Leaf pinnately to subpalmately compound (axis apparent beyond lowermost leaflets); leaflets 2–many |
| |
| | 29. Leaflets 2, main axis ending as a tendril or bristle |
| LATHYRUS |
| | 29' Leaflets 3 or more, main axis ending as a leaflet, tendril, or bristle |
| |
| | 30. Leaflets 3; fruit (except Phaseolus) generally indehiscent |
| |
| | 31. Keel petals spirally coiled; leaflet generally lobed — trailing or twining vine |
| PHASEOLUS (no key) |
| | 31' Keel petals not spirally coiled; leaflet margin entire, toothed, or wavy |
| |
| | 32. Leaflet margin toothed or wavy — fruit ovoid or reniform, generally 1-seeded, or ± coiled, several-seeded |
| |
| | 33. Corolla persistent, enclosing fruit, yellow, 3.5–5 mm |
| TRIFOLIUM |
| | 33' Corolla deciduous, various in color and size, including above |
| |
| | 34. Fruit spirally coiled, rarely only sickle-shaped, generally prickly; seeds > 2 |
| MEDICAGO |
| | 34' Fruit not spirally coiled, not prickly; seeds 1–2 |
| |
| | 35. Fruit reniform, with curved ridges; corolla 2–3 mm |
| MEDICAGO |
| | 35' Fruit ovoid, with transverse ridges or a ± distinct network of lines; corolla 2.5–7 mm |
| MELILOTUS |
| | 32' Leaflet margins not toothed, not wavy |
| |
| | 36. Plant ± gland-dotted; seed 1; fruit, except beak, generally included in calyx |
| |
| | 37. Corolla at least partly blue to purple; calyx not swollen in fruit |
| HOITA |
| | 37' Corolla white to yellow; calyx conspicuously swollen in fruit |
| RUPERTIA |
| | 36' Plant not gland-dotted; seeds generally 2–several; fruit exserted from calyx or including except for beak |
| |
| | 38. Inflorescence a raceme; fruit exserted from calyx |
| ASTRAGALUS |
| | 38' Inflorescence an umbel; fruit exserted from calyx or including except for beak |
| LOTUS |
| | 30' Leaflets > 3 on all or most leaves; fruit dehiscent or indehiscent |
| |
| | 39. Leaf even-pinnate, main axis ending as a bristle or tendril |
| |
| | 40. Calyx lobes > 2 × tube; plant hairy — flowers 1–3 at peduncle tip |
| LENS (no key) |
| | 40' Calyx lobes, some or all, < 2 × tube; plant glabrous or hairy |
| |
| | 41. Leaflets 30–60; fruit either 15–20 cm or wavy-margined and breaking into 1-seeded segments |
| |
| | 42. Fruit wavy-margined and breaking into 1-seeded segments; flowers 8–11 mm |
| AESCHYNOMENE (no key) |
| | 42' Fruit 15–20 cm, neither wavy-margined nor breaking into 1-seeded segments; flowers 10–18 mm |
| SESBANIA (no key) |
| | 41' Leaflets < 30; fruit < 8 cm, not wavy-margined or 1-seeded |
| |
| | 43. Stipules leaflet-like, often > leaflets; style longitudinally folded, opening on convex side; leaflets 4–6, glabrous — waif |
| PISUM (no key) |
| | 43' Stipules generally not leaflet-like but sometimes ± = leaflets; style not folded; leaflets 4–many, hairy or glabrous |
| |
| | 44. Style ± flat, puberulent on concave side ± 1/3–1/2 length; leaflets ± rolled in bud |
| LATHYRUS |
| | 44' Style generally round in X-section, puberulent all around at tip or mostly on convex side; leaflets folded in bud |
| VICIA |
| | 39' Leaf odd-pinnate, main axis ending as a leaflet |
| |
| | 45. Corolla wings tiny, << keel; leaflet upper sides finely red-dotted; fruit 1-seeded, leathery, strongly net-ridged |
| ONOBRYCHIS (no key) |
| | 45' Corolla wings not tiny, ± = keel; leaflets not red-dotted (may be dark gland-dotted); fruit without above combination of traits |
| |
| | 46. Plant gland-dotted on stems, leaflets, or both; fruit indehiscent |
| |
| | 47. Fruit several-seeded, long-exserted from calyx, generally prickly; leaflets 6–10 mm wide |
| GLYCYRRHIZA |
| | 47' Fruit 1-seeded, included in calyx, glandular; leaflets generally < 6 mm wide |
| |
| | 48. Petals all arising from receptacle; stamens 10; inflorescence sometimes head-like |
| PSOROTHAMNUS |
| | 48' Petals, except banner, arising from side or top of column of fused filaments; stamens 5 or 9–10; inflorescence not head-like |
| |
| | 49. Plant prostrate or decumbent |
| |
| DALEA |
| MARINA |
| | 49' Plant erect or ascending |
| |
| | 51. Inflorescence a dense spike; stamens 5 |
| DALEA |
| | 51' Inflorescence an open raceme; stamens 9–10 |
| MARINA |
| | 46' Plant not obviously gland-dotted; fruit dehiscent or indehiscent |
| |
| | 52. Inflorescence an umbel; flowers many, sometimes 2–3 |
| LOTUS |
| | 52' Inflorescence a spike or raceme, sometimes head-like; flowers many, rarely 1–2 |
| |
| | 53. Seed 1; leaflet with a single, large gland at tip; inflorescence a dense spike, ± 1 cm — flower 5–5.5 mm |
| MARINA |
| | 53' Seeds several; leaflet without a gland at tip; inflorescence a raceme or spike |
| |
| | 54. Fruit indehiscent, breaking into 1-seeded segments; corolla 6–9 mm; leaflet generally < 6 mm |
| ORNITHOPUS |
| | 54' Fruit generally dehiscent, sometimes slowly so, not breaking into 1-seeded segments; corolla often > 9 mm; leaflet often > 6 mm |
| |
| | 55. Stigma or style tip finely hairy — fruit base stalk-like |
| |
| | 56. Stipules spiny; fruit not inflated; flowers white to pink |
| PETERIA (no key) |
| | 56' Stipules 0 or spiny; fruit inflated; flowers red |
| SPHAEROPHYSA (no key) |
| | 55' Stigma and style glabrous |
| |
| | 57. Keel tip rounded to acute, rarely short-beaked; fruit 1-chambered or, if 2-chambered, septum arising from lower suture (rarely a narrow flange from upper suture also present) |
| ASTRAGALUS |
| | 57' Keel tip distinctly beaked; fruit generally 2-chambered, the partial or complete septum arising from upper suture |
| OXYTROPIS
|