Lepidium densiflorum Schrad.
Family: Brassicaceae
prairie pepper-weed, small peppergrass
Lepidium densiflorum image
Robert W. Freckmann  
Etymology: Lepidium: from the Greek lepidion, meaning "a little scale," in reference to the shape of the fruit pods
Plants: erect, annual/biennial, 8"-20" tall forb, with thin short hairs
Leaves: lower leaves coarsely toothed to pinnately-divided; the upper leaves not clasping
Flowers: 4-parted, either no petals or shorter than the sepals; inflorescence a 2"- 4" long cluster (raceme) of stalked flowers; blooms May-June
Fruits: oval, flat pod usually widest above the middle, notched at the tip fruit drawing
Habitat: dry to moist; disturbed areas, fields, roadsides
Conservation Status: Introduced - naturalized