59 



lla. Stem pubescent or glabrate; leaflets seldom more than 5 cm. 



long Hog Peanut, Amphicarpa monoica, 



lib. Stem villous with retrorse hairs; leaflets usually longer than 5 



cm. Hog Peanut, Amphicarpa pitcher!. 



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 1 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 812 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 carolmiana. 



17a. Flowers yellowish-white Vetchling, Lathyrns ochroleucus. 



17b. Flowers purple 18. 



18a. Stipules nearly regularly halberd-shape, almost as large 



as the leaflets Beach Pea, Lathyrns maritimus. 



ISb. Stipules half-sagittate, apparently attached laterally near 



the middle 19. 

 19a. Leaflets 4 8 pairs, ovate; racemes with 10 or more flowers 



Wild Pea, Lathyrns 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. 



