Crotalaria trichotoma Bojer

Crotalaria trichotoma is an erect annual or short-lived perennial herb, up to 2.7 m tall, stem ribbed, appressed puberulous. Leaves trifoliate, without stipules; petiole 2-5 cm long; leaflets lanceolate to elliptical-oblong, 4-14 cm x 1-4 cm, base acuminate, apex acute or rounded, glabrous or rarely puberulous above, appressed puberulous below. Inflorescence a terminal raceme, 30-40 (-90) cm long, flowers many, closely arranged; pedicel 4-8 mm long; calyx becoming truncate at base and deflexed against the pedicel, 4-6 mm long, glabrous or thinly appressed puberulous, the 5 lobes reduced to small, widely spaced teeth. Pod shortly stipicate, sub-cylindrical, inflated, (30-) 35-45 mm x 7-11 mm, black when ripe, appressed puberulous, 50-70-seeded. Seed obliquely heart-shaped, 2-3 mm long, smooth, orange-buff or terracotta. The genus name ‘Crotalaria’, meaning rattle, is indicative of the noise made by the seeds shaken in the mature pods. The specific epithet means having divisions always in threes in reference to the leaves.

C. trichotoma flowers are believed to be pollinated by insects before they open, suggesting cleistogamy and self-incompatibility.

C. trichotoma is a plant of the humid tropics. It grows on grassy sites in coastal forest clearings, bushland, Brachystegia woodland, grasslands, roadsides and cultivated fields. It is fairly tolerant to drought.

C. trichotoma originates from the coastal regions of Tanzania and Mozambique. It was introduced into Java in 1916 and soon spread to Sumatra where it occasionally escapes from cultivation, but does not seem to naturalize. It has become widespread in the humid tropics.

C. trichotoma is propagated by seed. Direct seeding at the rate of 2.5-3.5 kg/ha is most common.

Planting in strips 0.3-1 m apart is recommended. Weeding twice is generally required before the crop covers the ground, which occurs after 3-4 months. Once established, C. trichotoma propagates abundantly by self-seeding. It is short-lived and does not tolerate frequent heavy lopping. Cutting should be done at a height of 40-60 cm above the ground, always leaving a few leaves.

C. trichotoma is severely attacked by the fungus Parodiella spegazzinii, which covers the upper surface of the leaves with a black soot-like layer causing them to curve upwards. It is occasionally ravaged by Helopeltis antonii and less severely by Deiopeia pulchella.

Reclamation: C. trichotoma performs better on degraded and compacted soils than other green manure crops and can be used for reclamation. Soil improver: The plant is grown as green manure and cover crop in tea, coffee, rubber and citrus plantations. Intercropping: It has been used as an intercrop with annual crops such as maize.

Fodder: Leaves and stems are very nutritious and are readily eaten by cattle and horses. They contain no alkaloids unlike many other species in the genus. It is grown for fodder often mixed with grasses. Fibre: Bark contains fibre that can be used for cordage.