Duration: Perennial

Nativity: Native

Lifeform: Forb/Herb

General: Herbaceous to suffrutescent perennials, occasionally as a small tree, to 1 m tall or more, unarmed, stems leafy, herbage densely hairy, ill-smelling.

Leaves: Alternate, compound, even-pinnate, leaflets in 4-8 opposite pairs, each oblong to narrowly oblanceolate or elliptic, 2.5-4.5 cm long, densely hairy and paler in color beneath, petioles with a large gland near the base, stipules lanceolate, lasting only a short time (ephemeral), 3.5-7 mm long.

Flowers: Yellow, showy, asymmetric (caesalpinioid), petals obovate, flat, 12-19 mm long, stamens 5-10, bracts falling before the flowers open, inflorescences many flowered and axillary or terminal in large paniculate racemes.

Fruits: Pods, oblong, 8-12 cm long, inflated, indehiscent, not shiny at maturiy. Seeds several.

Ecology: Found along streams and washes, in disturbed areas and roadsides, from 2,500-5,000 ft (762-1524 m); flowering July-September.

Distribution: s AZ, s NM; south to S. Amer.; also in Africa, Australia and Asia.

Notes: Distinguished by being tall, the powerful stench, the dense, short pubescence all over, 4-8 pairs of acute leaflets and large, caesalpinoid yellow showy flowers. Look for this species under Cassia leptocarpa in older texts, also, in Jepson, see Senna multiglandulosa [Cassia tomentosa]. Jepson notes that this species is often planted along highways.

Ethnobotany: There is no use recorded for this species, but other species in this genus have uses.

Etymology: Senna is from the Arabic name Sana, while hirsuta means covered with hair.

Synonyms: Many, see Tropicos

Editor: LCrumbacher 2012, FSCoburn 2015