It is an erect or spreading shrub or herbaceous perennial with pinnate leaves, with two to six pairs of egg-shaped leaflets, and yellow flowers arranged in groups of two to six, with six fertile stamens and four staminodes in each flower.

Senna hirsuta is an erect or spreading shrub or herbaceous perennial that typically grows to a height of up to 2.5 m (8 ft 2 in).

The flowers are yellow and arranged on the ends of branches and in upper leaf axils in groups of two to five on a peduncle about 10 mm (0.39 in) long, each flower on a pedicel 12–20 mm (0.47–0.79 in) long.

[4][5] In 1979, Howard Samuel Irwin and Rupert Charles Barneby transferred the species to the genus Senna as S. hirsuta in the journal Phytologia.

[7] In the same journal, Irwin and Barneby described seven varieties of S. hirsuta, and the names are accepted by Plants of the World Online: Senna hirsuta is native to most countries in South America, to Nicaragua, Honduras and Cuba in Central America, and to Arizona, New Mexico, Mexico and Puerto Rico in North America.