Angiosperms: Dicotyledons

Fabaceae
Legume Family

• Stem: annual; 1 1/2’ to 3’ tall; unbranched; hairy.
• Leaves: alternate; pinnately compound, 2” by 3/4”; leaflets 1/2” by 1/8”, rounded bases, tips rounded with a point, eight to twelve pairs per leaf; leaflets with stiff marginal hairs.
• Inflorescence: one or a few flowers in the leaf axils on the upper half of the stem.
• Flowers: petals yellow, 1/2” long, the flower cup-shaped; brown stamens, 3/16” long; sepals lance-shaped, 1/4” long; flowering from mid-July to mid-August.
• Fruits: pods, 2” by 3/16”, flat, brown, with hairy margins; seeds squarish, flat, 1/8” long, black, shiny; as they dry pods split into two halves and twist, scattering the seeds; fruiting begins in late July; seeds are shed beginning in mid-August.
• Habitat: common on dry, sandy prairies, on roadsides, and in open places.
• Bibliography from Biodiversity Heritage Library
• Vascular Plants of Iowa