Tephrosia purpurea (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Tephrosia purpurea (L.) Pers.

Protologue: Syn. pl. 2: 329 (1807).

Family: Leguminosae - Papilionoideae

Chromosome number: 2n= 24

Synonyms

• Cracca purpurea L. (1753),
• Tephrosia diffusa (Roxb.) Wight & Arnott (1834),
• T. wallichii Grah. ex Fawc. & Rendle (1917).

Vernacular names

• Purple tephrosia, wild indigo (En). Fish poison (Am).
• Indigo sauvage (Fr)
• Indonesia: pohon nila hutan (Java)
• Philippines: balatong-pula, balba-latong, tina-tinaan (Tagalog)
• Cambodia: trôm" khmaôch
• Laos: s'a:z kh'a:m moyz (Louang Prabang)
• Thailand: khram-pa (northern)
• Vietnam: cây cốt khí tía, ve cái, doãn kiềm dỏ.

Origin and geographic distribution

T. purpurea is native to tropical Asia, and is found from India and Sri Lanka to southern China, and through South-East Asia to tropical Australia and the Polynesian Islands. It is now naturalized and cultivated pantropically.

Uses

T. purpurea is used as green manure for vegetables, rice, coconut and banana, especially in India and Sri Lanka, and on a more limited scale in Indonesia, Malaysia and southern China. It is also applied as temporary shade. When grown as a green manure on saline-sodic soils in Rajastan (India), it is most successful in reducing soil salinity and lowering the pH. In northern India, dry plants are collected for fuel. In Indo-China the seeds are used as a substitute for coffee. The leaves are occasionally used to dye orange-brown, or, in a mixture with Mucuna cyanosperma Schumann, black.

Medicinally, all parts of the plant have tonic and laxative properties. The dried plant is deobstruent, diuretic and useful in treating bronchitis, bilious febrile attacks and obstructions of the liver, spleen and kidneys. It is also recommended as a blood purifier, in the treatment of boils and pimples and is considered a cordial treatment. In southern India, a decoction of the fruit is given against intestinal worms and a fruit extract is used to relieve bodily pains and inflammatory problems. The roots are bitter and a decoction is used as a nematicide for treatment against Toxocora canis larvae which cause a lung disease in Sri Lanka; it is also used against dyspepsia, colic, and chronic diarrhoea and as anthelminthic. Pounded leaves are used to stupefy and catch fish. Information on the fodder value of T. purpurea is conflicting. In India and in South Africa, it is used as a fodder before flowering, but in Australia it is reported to cause livestock poisoning.

Properties

Green manure of T. purpurea grown in Rajastan (India) contains per 100 g dry matter: C 36 g, N 1.9 g, P 0.3 g, K 1.8 g, Ca 1.8 g, Mg 0.8 g, S 0.4 g. The energy value of the wood of T. purpurea is 14 500 kJ/kg. The toxic properties of T. purpurea are due to the presence of flavonoids; those recorded include rotenone and several of its isomers named deguelins. One of the deguelins, tephrosin, is poisonous to fish, but not to mammals. The leaves contain up to 2.5% rutin (a flavonol glucoside). The poisonous compounds occur in too low concentrations in the plant to be extracted commercially.

Botany

• An erect or spreading annual or short-lived perennial herb, sometimes bushy, 40-80 cm tall, rarely up to 1.5 m; indumentum sericeous, strigose or velutinous; stem slender, erect or decumbent at base.
• Leaves imparipinnate; stipules narrowly triangular, 1.5-9 mm × 0.1-1.5 mm; rachis up to 14.5 cm long, including the petiole of up to 1 cm; petiolule 1-3 mm long; leaflets 5-25, obovate to narrowly elliptical, terminal leaflet 7-28 mm × 2-11 mm, lateral leaflets 5-30 mm × 2-11 mm, acute at base, apex rounded to emarginate, venation usually distinct on both surfaces.
• Inflorescence an axillary or leaf-opposed pseudo-raceme, (1.5-)10-15(-25) cm long, sometimes with basal leaf-like bracts; flowers in fascicles of 4-6; bracts to fascicles and to flowers small, bracteoles usually absent; pedicel 2-6 mm long.
• Flower 4-8.5 mm long, purplish to white; calyx campanulate, persistent, cup 1.4-2.3 mm × 1.5-3.2 mm, unequally 4-toothed, teeth pubescent inside; standard broadly ovate, 3.5-7.3 mm × 5-10 mm, clawed; wings 2.5-6 mm × 1.5-3.8 mm, auricled on vexillary side, clawed; keel 2.2-4.5 mm × 2-3 mm, auricled on vexillary side, clawed; stamens 10, staminal tube 4-6 mm long, filaments alternately longer and shorter, free part up to 3.5 mm long, vexillary filament free at base, connate halfway, 5-8 mm long; style up to 4.5 mm long, upper half glabrous, stigma penicillate at base.
• Pod flat, linear, 2-4.5 cm × 3-5 mm, somewhat up-curved towards the end, convex around the seeds, flattened between, margins thickened, dehiscent with twisted valves, 2-8(-10)-seeded.
• Seed rectangular to transversely ellipsoid, 2.5-5 mm × 1.8-3 mm, light to dark brown to black, sometimes mottled.

T. purpurea is associated with the vesicular-arbuscular mycorrhizal fungi Glomus heterosporum and Sclerocystis microcarpus in waste sites of coal mines and calcite mine spoils, and is nodulated by Rhizobium. It flowers throughout the year in Java.

T. purpurea is a very variable species and many subclassifications exist. Most characteristic is the shape of its pod: convex around the seeds with a distinctive flat area in between. The name T. purpurea is often erroneously applied to the cultivated T. noctiflora Bojer ex Baker which has longer inflorescences, a very long carinal calyx tooth and reticulately ridged seeds.

For South-East Asia T. purpurea is subclassified as follows:

• subsp. barbigera Bosman & de Haas: vexillary filament and staminal tube velutinous; occurring in the Philippines, New Guinea and Australia. Based on flower and inflorescence lengths, further subdivided into 2 varieties: var. barbigera (flower 7-8 mm long, longest inflorescence 11-19.5 cm long) and var. rufescens Benth. (flower 5-6 mm long, longest inflorescence 4.5-11 cm long).

• subsp. purpurea: characteristics and distribution as described for the species; vexillary filament and staminal tube glabrous.

Ecology

T. purpurea occurs naturally in grassy fields, waste places and thickets, on ridges, and along roadsides, in Java up to 400 m altitude. It generally grows at low altitudes, but may be found to 1300 m altitude. In Hawaii, it grows near the seashore. It prefers dry, gravelly or rocky and sandy soils, but in Madras (India) it grows well on loamy soils. It is tolerant of saline-sodic soil conditions.

Agronomy

T. purpurea can easily be propagated by seed. Its growth is often not very luxuriant, limiting its value as a temporary shade crop or green manure. When added to the soil as green manure it increases humus content and induces the formation of large, stable soil aggregates. It produces ample seed and builds up a large seedbank in the soil.

Genetic resources and breeding

A small germplasm collection is maintained at the Southern Regional Plant Introduction Station, Griffin, Georgia, the United States. There is no breeding programme.

Prospects

T. purpurea is not generally recommended as a green manure and temporary shade crop, but may nevertheless be useful on saline-sodic soils. It deserves further testing for medicinal uses.

Literature

• Bhatnagar, R., 1986. Chemical analysis of Tephrosia purpurea. Transactions of the Indian Society of Desert Technology and University Centre of Desert Studies 11: 99-100.
• Bosman, H.T.M. & de Haas, A.J.P., 1983. A revision of the genus Tephrosia (Leguminosae - Papilionoideae) in Malesia. Blumea 28: 421-487.
• Botton, H., 1957. Les plantes de couverture. Guide pratique de reconnaissance et d'utilisation des Légumineuses en Côte d'Ivoire [Cover crops. A practical guide for the identification and utilization of legumes in Ivory coast]. Journal d'Agriculture Tropicale et de Botanique Appliquée 4(12): 610-613.
• Gupta, P.K. & Karan, F., 1985. Prospects of utilizing the common wild herbs and shrubs for the reclamation of saline-sodic soils. Transactions of the Indian Society of Desert Technology and University Centre of Desert Studies 10: 39-44.
• Kiuchi, F.Y., Chen, X., Tsuda, Y., Kondo, K. & Kamar, V., 1989. Studies on crude drugs effective on visceral larva migrans. 11. Identification of nematicidal principles in Tephrosia purpurea Pers. Shyoyakugaku Zasshi 43:(1): 42-49.
• Pandey, Y.N., 1975. A study on an important drug plant Tephrosia purpurea Pers. Quarterly Journal of Crude Drug Research 13: 65-68.
• Raina, S.N., Srivastav, P.K. & Rama Rao, S., 1986. Nuclear DNA variation in Tephrosia. Genetica 69: 27-33.

Authors

• N.O. Aguilar