KEY TO THE GENERA OF MANHATTAN PLANTS. 19 



6 Elongated, usually twisted; seeds oblong 5x13 mm. 



Thorny trees Gleditschia. 102 



7. Coiled spirally, several seeded. Herbs Medicago. 103 



7. Not coiled 8 



8. Ventral suture, wing margined, legume thin and flat. 9 



8. Not winged 10 



9. Legume rounded above. Trees Bobinia. 104 



9. Legume acute at both ends. Trees Cercis. 105 



10. Seeds separated by transverse partitions 11 



10. No transverse partitions 12 



11. Legumes in racemes, several seeded Cassia. 106 



11 . Legumes in heads, few seeded Acuan. 107 



12. Legume and seeds flat. Vines 13 



12. Legume terete or somewhat flattened 14 



13. Ciliate margined, 3 to 4 cm long Falcata. 108 



13. Glabrous, margin thickened, 10 cm long Apios. 109 



14. Seeds globular, valves glabrous, not conspicuously 



coiled in dehiscence 23 



14. Seeds oblong or angular, valves pubesent, tightly 



coiled in dehiscence. Vines Phaseolus. 110 



15. Legume enclosed in the persistent calyx and corolla; 



in heads ; small and thin, few seeded Trifolium. Ill 



15. Corolla deciduous 16 



16. Legume several seeded, usually inflated 17 



16. Legume 1-2-seeded 19 



17. Strongly beaked and stipitate, tardily dehiscent, 



seeds numerous ; calyx persistent Baptisia. 112 



17. Not conspicuously beaked or stipitate 18 



18. One-celled, inflated, dehiscent, seeds rattling in the 



pod Crotalaria. 113 



18 Two-celled and inflated, or 1-celled and turgid, 



slightly or tardily dehiscent, oblong or ovoid Astragalus. 114 



19. Flat, orbicular, reticulated, 1-seeded, included in 



the calyx Lespedeza. 115 



19. Not as above 20 



20. In dense spikes, included in calyx, not flattened Kuhnistera. 116 



20. Terete, oblong, not included in calyx 21 



20. Flattened or globose, or if oblong, enclosed in calyx 22 



21 . Canescent or glandular. Shrubs Amorpha. 1 17 



21. Glabrous. Herbs Melilot us. 118 



22. Calyx teeth long, persistent, very villose Parosela. 119 



22. Calyx teeth, not villose ; legume indehiscent Psoralea. 120 



23. Five to six cm long, 1 cm wide Lathyrus. 121 



23. Two to three cm long, one-half cm wide Vicia. 122 



