Senna fruticosa

Author: (Mill.) Irwin & Barnaby

Morphological description
Shrub or small tree up to 6 m high, all young parts greyish pubescent. Stipules linear, 3-4 mm long, early caducous.

Leaves (fruticosa Senna Rel Houst ) paripinnate with 2 pairs of leaflets; petiole slender, puberulous, c. 3 cm long; rachis slender 1-3 cm, bearing an oblong, nipple-shaped gland between the lower pair of leaflets; petiolules c. 3 mm. Leaflets membranaceous, obliquely ovate, very unequal-sided, upper pair much larger than the lower one, 4-16 by 2-7 cm; glabrous or glabrescent on upper side, puberulous on lower; apex acute to acuminate, base obliquely cuneate.

Inflorescence: Racemes short, densely flowered, up to 6 cm long including the 2 cm peduncle; bracts narrowly lanceolate to subulate, 2-4 mm, early caducous; bracteoles absent;pedicels long, slender, puberulous, 2-3 cm.

Flower: Sepals 5, oblong-obovate, yellowish-green often mingled with red, puberulous, 7-11 mm. Petals 5, yellow, pubescent on both sides, broadly obovate to orbicular, 2-2.5 cm. Stamens 7 (or 6): 3 with filaments filiform, 2-4 mm long and anthers glabrous, strongly curved, 6-7 mm, rostrate at apex, opening by an apical pore; 4 (or 3) with filaments dilated distally, 2-3 mm and anthers similar but thicker and 8-9 mm long; upper 3 stamens usually absent; filaments of all stamens straight. Ovary sessile, densely appressed pubescent, style slender, stigma inconspicuous.

Pods terete, pendulous on a short, stout stipe, 15-25 cm long, 1-1.5 cm in diameter, long beaked, slightly annulate (fruticosa Senna Rel Houst ).

Seeds 80-100 embedded in a foetid, black pulp, compressed ovoid, 5-6 mm, dark brown.

Indigenous to Mexico and C America. Cultivated throughout the tropics as ornamental, also in the Malesian area (recorded from Java, Celebes, New Guinea). It seems rarely to have escaped cultivation and become naturalized. Seed setting is said to be poor.

De Wit (1956: 247) reports to have observed a single specimen found in the shade of a sagu-swamp in Celebes.

Commonly grown as ornamental.