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.=

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