Angiosperms: Dicotyledons

Fabaceae
Legume Family

• Stem: annual; 1’ tall; branching near the base; stiff-hairy.
• Leaves: alternate; oval with tapered bases and pointed tips; sessile; 1 5/8” by 7/16”; basal leaflets (stipules) pointed, stiff-hairy, extending on to the stem as a wing; stiff-hairy above and below.
• Inflorescence: one to several flowers on 1” to 4” hairy stalks from the upper leaf axils.
• Flowers: corolla yellow, not extending much beyond the calyx; calyx 3/8” long, deeply lobed with sharp points, hairy; flowering over a long period from mid-July to late September.
• Fruits: pods inflated, 3/4” long by 3/8” in diameter, light tan becoming dark brown at maturity; seeds rattle within when shaken, fruiting begins in late July.
• Habitat: infrequent on sandy prairies, also in open woods, in ridge openings, and on sand dunes; more common in the southern part of Iowa.
• Bibliography from Biodiversity Heritage Library
• Vascular Plants of Iowa