Senna bauhinioides (A. Gray) Irwin & Barneby (redirected from: Cassia bauhinioides var. arizonica)
Family: Fabaceae
[Cassia bauhinioides A. Gray,  more...]
Senna bauhinioides image

Senna bauhinioides is a spreading low plant with gray-green foliage. The yellow flowers frequently only partly open. The fruit is a plump pod. The leaves are paired. Senna bauhinioides is found in dry sandy areas at lower elevation.

Correll and Johnston 1970, Allred and Ivey 2012

Duration: Perennial

Nativity: Native

Lifeform: Subshrub

General: Perennial herb to subshrub, 10-40 cm tall, from slender woody rootstock; stems several, ascending-spreading and usually branched, gray-tomentose, sometimes slightly woody near the base.

Leaves: Alternate, on slender ascending petioles, 1-3 cm long, with linear stipules 3-6 mm long; at the end of each petiole there is a slender erect gland and one pair of leaflets; leaflets oblong, 1-3 cm long and 5-12 mm wide with a rounded tip and a strongly asymmetric, rounded base; leaflet surfaces silky-pubescent and slightly cinereous (ash-colored from the hairs).

Flowers: Yellow, in few-flowered panicles at branch tips, on peduncles 2-4 cm long; flowers about 3 cm wide, appearing mostly radially symmetrical (caesalpinioid); sepals 5, oblong, 6-8 mm long, hairy, green with yellowish margins; petals 5, yellow, 12-18 mm long, with brown veins that are especially distinct when flowers are dried.

Fruits: Pods oblong and curved into a slight hook shape, 2-4 cm long and 5-6 mm wide, dark brown and pubescent; splitting open along 2 suture lines to release 8-15 seeds.

Ecology: Found on gravelly flats and plains, along washes, and rocky slopes, from 2,000-5,500 ft (610-1676 m); flowers April-August.

Distribution: AZ, NM, TX; south to n MEX.

Notes: Distinguished by being an erect-ascending perennial; each leaf consisting of 1 pair of gray-green leaflets (S. covesii has 3-4 pairs per leaf) which are silky-pubescent and have small, erect glands at the bases (use your hand lens); the bright yellow, showy caesalpinoid flowers; and pods which "elastically" dehisce, sending seeds flying, the shells becoming brown and hard and peeling backward.

Ethnobotany: Unknown, but other species in the genus have uses.

Etymology: Senna is from Arabic word sana, meaning bright and clear, alluding to the laxative nature of the leaves and pods; bauhinioides means resembling the genus Bauhinia, which also has leaflets in pairs.

Synonyms: Cassia bauhinioides

Editor: SBuckley 2010, FSCoburn 2015, AHazelton 2017