Desmodium adscendens (Swartz) DC.

Desmodium adscendens (Swartz) DC.

Family

Leguminosae-Papilionoideae

Synonyms

Hedysarum adscendens Sw., Desmodium oxalidifolium G. Don, Desmodium trifoliastrum Miquel.

Vernacular Names

English Tick clover, sweetheart (Dominica), adscendens (South America).
Philippines Pega pega.
Vietnam Bai ngai.
American Zarzabacoa galana.

Geographical Distributions

Desmodium adscendens occurs naturally in tropical Africa and South America. It has been introduced throughout South and Southeast Asia and Melanesia.

Description

D. adscendens is a creeping or ascending perennial herb or low shrub that can reach up to 1 m long and with a diffuse taproot. The stem is cylindrical, often rooting near the base, striate, with densely soft hairy and glabrescent.

The leaves are trifoliolate. The stipules are obliquely ovate-lance-shaped with long attenuate at the apex, measuring up to 1 cm x 3 mm and persistent. The petiole is 1-3 cm long while the rachis measures up to 1 cm long where both are hairy. The leaflets are elliptical-obovate, with terminal leaflet measuring (1.5-)2-4(-5.5) cm x 1-3 cm while the lateral leaflets are smaller, wedge-shaped to rounded at the base, entire at the margin, obtuse and emarginate at the apex. The upper surface is hairless to sparsely pubescent while the lower surface is sparsely to densely soft hairy. The lateral nerves are rather distinct and not reaching the margin. They are 4-7 on either side of the midrib.

The inflorescence is a terminal or axillary raceme, measures 4-20 cm long and with lax-flowered. The flowers are usually in pairs. The bracts are ovate with a long acuminate apex, measuring 4-6(-11) mm x 1.5 x 2.5 mm, with densely pubescent and early caduceus. The pedicel is slender, measures up to 2 cm long in fruit, densely covered with mixed, spreading, hooked and straight hairs less than 1 mm long. The bracteoles are absent. The sepal is 2.5-3.0 mm long, covered with persistent, patent and long hairs especially on the 5 teeth and with minute straight or hooked hairs. The petal is white or purple to violet. It is broadly obovate or orbicular, measuring 4.5-5.5 mm x 4.0-4.5 mm, rounded or retuse at the apex and with short clawed. The wings are nearly obovate, measuring about 4 mm x 2 mm, obtuse at the apex, auriculate at the base and with short clawed. The keel-petals are 4.5-5.0 mm long, incurved, sub-acute at the apex and with distinctly long-clawed. The claw is 2-3 mm long. The stamens are diadelphous. The pistil is 5.0-5.5 mm long, densely short-hairy on the ovary, hairless style and with a minutely capitates stigma.

The pod is narrowly oblong, measuring 1.0-2.5 cm x 3-4 mm, 3-6-jointed, dehiscent along the lower sutures, rarely short (1-2 mm) stipitate, slightly swollen on the seed, densely covered with very short, spreading and hooked hairs. The seed is flattened, ellipsoid and measuring 2.5-5.0 mm x 1.5 mm.

Ecology / Cultivation

D. adscendens occurs in damp swamp forests and other humid where locations like stream banks and bunds of rice fields provided shady to them In equatorial regions, it is found from 200-1000 m altitudes. In Java, it flowers year-round. In the subtropics, it flowers late in the growing season.

Line Drawing / Photograph

Desmodium_adscendens

References

  1. Plant Resources of South-East Asia No. 11: Auxiliary plants.