This native annual plant is about 2' tall and largely unbranched, except near the base. The major stems are stout, round, and covered with rather long glandular hairs, especially where new growth occurs. The lower and middle compound leaves along the stems are trifoliate with long petioles. The individual leaflets are about 1½" long and ½" across. They are oval, ovate, or oblong, and have smooth margins that are slightly ciliate. Their surface is dull green and covered with short fuzzy hairs, with longer hairs occurring along the lower central vein. When the foliage is bruised or rubbed against, a fetid odor is emitted. Smaller leaves on short petioles occur along the upper stems that are simple, rather than compound. The major stems terminate in racemes of flowers of variable length – these flowers are whorled near the apex of the stems with scattered seedpods below. Each flower is about 1" across and has an unusual structure. There are 4 white petals about ½" long that are heart-shaped, but with a long narrow base. About 8-12 strongly exerted stamens are reddish purple and rather unequal in length, with the upper stamens about twice the length of the petals. The single slender style is much shorter than the stamens and less conspicuous. At the base of each flower, is a gland that secretes a conspicuous drop of bright red fluid. The calyx is divided into 4 triangular sepals that are reddish purple. The flowers occur on long hairy pedicels. The blooming period occurs from summer until the fall, and can last several months. There is no obvious floral scent. Pollinated flowers develop sizeable seedpods up to 3" long that are sessile against the pedicels (i.e., there is no stipular growth at the base of the seedpods). These seedpods resemble stout bean pods that can divide into two halves. Each seedpod has fuzzy hairs on the outer surface, and forms a long terminal spike that withers away as the seedpod matures. Mature seedpods are held more or less erect, rather than drooping downward from the stems. The individual seeds have an irregular patterned surface. The root system consists of a long taproot without rhizomes. This plant spreads by reseeding itself.
