Twinleaf senna, Twoleaf senna

Senna roemariana (Scheele) Irwin & Barneby

Fabaceae (Legume family)


Twinleaf senna is an erect, perennial herb in the Legume family. The plant is green and covered with short, soft hairs which give it a grayis appearance. Twinleaf senna can have a few or many stems arising from a thickened root.

The leaves are arranged spirally as pairs of leaflets (hence the name twinleaf). The pairs of leaflets fold together during dry periods to conserve moisture.

Deep yellow flowers emerge from April to August; each has five petals that are about twice as long as the sepals, which are the usually green flower parts that surround and protect the bud. The flower stamens, or pollen-bearing organs, are straw-colored to light brown. A bean-type fruit develops after flowering.

This plant is poisonous to goats.


Twinleaf senna is common in pastures and open woods on limestone soils in Central and West Texas and westward to New Mexico.