Senna hirsuta (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Senna hirsuta (L.) Irwin & Barneby

Protologue: Phytologia 44 (7): 499 (1979).

Family: Leguminosae - Caesalpinioideae

Chromosome number: 2n= 28, 56; 2n= 16 + 1B is reported from Nigeria

Synonyms

• Cassia hirsuta L. (1753),
• C. leptocarpa Benth. (1849).

Vernacular names

• Woolly wild sensitive plant (En)
• Indonesia: kasingsat bulu (general), kasingsat (Sundanese)
• Malaysia: sinteng, kacang kayu
• Philippines: balbala tuñgan, katanda, tighiman (Tagalog)
• Thailand: phong pheng (northern), dapphit (peninsular)
• Vietnam: muồng rừng.

Origin and geographic distribution

S. hirsuta is a native of tropical America and is now distributed throughout Malesia, Indo-China, Thailand and most other countries in the Asian and African tropics. In Java, where it has long been known and has naturalized, it is more common in West Java than towards the east.

Uses

S. hirsuta is used as a green manure and forage plant. In Africa it is planted as a shade plant in young coffee plantations. The leaves and young pods are eaten, usually steamed or cooked in vegetable dishes or in salads. The unpleasant smell can be reduced by relatively long cooking. In Java the leaves are used medicinally for treating herpes. A decoction of the leaves is used against irritations of the skin in Thailand. In Laos the seeds are used as a substitute for coffee.

Production and international trade

S. hirsuta is very occasionally sold in village markets, but there are no production data.

Properties

The seed contains a water-soluble gum, though not in commercial quantities; it also contains a bi-anthraquinone and a tri-terpenoid, which may prove medicinally important. The weight of 1000 seeds is 4 g.

Botany

• Erect or diffuse, simple or several-stemmed herb, up to 2.5 m tall, becoming soft-woody with age, with a fetid smell, hairy but highly diverse in pubescence; twigs grooved and ribbed, densely hairy.
• Leaves simply paripinnate, 10-20 cm long; stipules linear-acute, 3-15 mm long, usually not persisting; petiole stout, up to 6.5 cm long, villose, above the insertion with a sessile, oblong gland; rachis 3-16 cm long, glandless; petiolules up to 3.5 mm long, slender, villose, often not quite opposite; leaflets 2-8 pairs, strongly accrescent distally, chartaceous, lanceolate-acuminate, 2-12.5 cm × 1-5 cm, 2-6 times as long as wide, slightly unequal-sided, base acute or rounded, dark green, roughly villose on both surfaces.
• Inflorescence an axillary or rarely terminal, 2-8-flowered raceme (up to 45 in South America), 1(-8) cm long, aggregate in leafy panicles; peduncle up to 3 cm long; bracts linear to lanceolate, 1.5-5 mm long, early caducous; bracteoles absent.
• Pedicel 1-2.5 cm long, pubescent; sepals 5, unequal, 2 outer ones small, orbicular, 4-7 mm long, hairy, 3 inner ones larger, 7-10 mm long, partly glabrous; petals 5, unequal, obovate, 8-28 m long, yellow, glabrous, short-clawed; stamens 10, 2 large with flat filaments 4-7 mm long and curved anthers 7-8 mm long opening by apical pores, 4 smaller and 4 staminodial; ovary woolly, recurved; style short, glabrous with hairy subapical stigma.
• Fruit a falcate to straight angular pod, 6-28 cm × 3-7 mm, septate, 50-90-seeded, strigose.
• Seed slightly compressed, orbicular, about 3 mm in diameter, dark olive coloured; areole narrowly elliptical, 0.5-2.5 mm long.

S. hirsuta is very variable and 7 varieties have been distinguished for South America. In South-East Asia, 2 varieties occur: var. hirsuta (widespread as a weed in South-East Asia and the rest of the Old World tropics; fruit straight, 11-15 cm × 4-6.5 mm, bristly-hirsute) and var. puberula Irwin & Barneby (widespread in South America, but in South-East Asia only present in the Philippines as a weed, fruit simply arched outward, 15-25 cm × 3-6 mm). In South-East Asia S. hirsuta flowers throughout the year. The usually numerous fruits are curved when young and straight when mature; they are characterized by somewhat raised, glabrescent sutures and woolly strigose sides.

The synonymous name Cassia hirsuta is still commonly used in the literature. Until the beginning of the 1980s, Cassia L. was considered to be a genus with over 500 species. The large genus Cassia L. emend. Gaertner has now been subdivided into 3 genera: Cassia (trees, some filaments curved, bracteoles present, no areoles on seed), Senna Miller (herbs, shrubs or trees, all filaments straight, bracteoles absent, areoles on seed) and Chamaecrista Moench (herbs or shrubs, all filaments straight, bracteoles present, no areoles on seed). Cassia now has about 30 species, Senna and Chamaecrista comprise about equal numbers of species.

Ecology

In South-East Asia S. hirsuta is found in plains and hilly areas up to about 700 m altitude. It grows spontaneously in waste locations, along roadsides, railway embankments, dry ditches and in secondary forest. It is found in gardens and fields as a weed and prefers open locations.

Agronomy

S. hirsuta is propagated by seed. As a green manure S. hirsuta is fast growing, easy to cut, coppices well and can produce considerable amounts of foliage material in a growth cycle of 8 months. Observations in Central Africa indicate that it competes poorly with weeds. It is very susceptible to Corticium salmonicolor and is also affected by a root disease (Rosellina sp.), and by Sclerotium rolfsii.

Prospects

S. hirsuta is one of the Senna species which has been proposed as a green manure crop. However, research has so far not confirmed its potential for green manure, pasture, or forage.

Literature

• Gill, L.S. & Husaini, S.W.H., 1985. Caryological evolution of the southern Nigerian Leguminosae. Revue de Cytologie et de Biologie Végétales. Le Botaniste 8: 3-31.
• Groth, D., Boaretto, M.R. & da Silva, R.N., 1983. Morfologia de sementes, frutos e plantas invasores em algunas culturas [Seed, fruit and plant morphology in weeds of several crops]. Revista Brasileira de Sementes 5: 151-182.
• Irwin, H.S. & Barneby, R.C., 1982. The American Cassiinae. A synoptical revision of Leguminosae tribe Cassieae subtribe Cassiinae in the New World. Memoirs of the New York Botanical Garden 35: 425-435.
• Larsen, K. & Larsen, S.S., 1984. Cassia. In: Smitinand, T. & Larsen, K. (Editors): Flora of Thailand. Vol. 4(1). Leguminosae-Caesalpinioideae. The Forest Herbarium, Royal Forest Department, Bangkok, Thailand. p. 113.
• Ochse, J.J. & Bakhuizen van den Brink, R.C., 1980. Vegetables of the Dutch East Indies. 3rd English edition (translation of "Indische Groenten", 1931). Asher, Amsterdam, the Netherlands. pp. 375-376.
• Verdcourt, B., 1979. A manual of New Guinea legumes. Botany Bulletin No 11. Office of Forests, Division of Botany, Lae, Papua New Guinea. pp. 45, 47.

Authors

• H. Sangat-Roemantyo