Excoecaria indica (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Excoecaria indica (Willd.) Muell. Arg.

Protologue: Linnaea 32: 123 (1863).

Family: Euphorbiaceae

Chromosome number: 2n= unknown

Synonyms

• Sapium indicum Willd. (1805),
• Stillingia indica (Willd.) Baillon (1858),
• Stillingia diversifolia Miq. (1861).

Vernacular names

• Mock willow (En)
• Indonesia: ai tui (Ambon), gurah (Kalimantan), tagewa (northern Halmahera)
• Malaysia: apid-apid, gurah (Sabah), ludai (Peninsular), buta-buta, bebuta, kayu mati buta
• Thailand: krahut, samo thale (central), ku-ra (Malay, peninsular)
• Vietnam: xoi-an, sòi tía.

Origin and geographic distribution

Mock-willow is very widely distributed. It is found in southern and eastern India, Burma, and further south and west through Malesia, Sumatra, Borneo, the Lesser Sunda Islands (Sumbawa), the Moluccas, except the Philippines, to New Guinea and the Solomon Islands.

Uses

The leaves can be used to prepare a dye, which gives yarn a greenish-yellow colour or rattan a dark colour. The dyed yarn will gain a black colour when buried in the mud. A black colour can also be obtained by mixing the dye with charcoal and coconut oil. This mixture was formerly used in Indonesia to dye artificial hair tassels or wigs made of pineapple fibre black. The dye is also mixed with other dyes.

The young fruits are used as a fish poison; the stupefied fish can be eaten safely. The hard, globose fruits are used by children as marbles. The ripe seeds are used as vegetable or as condiment, but the fruit-wall should be removed carefully, because the latex it contains blisters the skin.

The timber is of poor quality and is not used. The wood is used as fuel; it burns well.

In Malaysia the leaves are externally applied as a febrifuge, and an infusion is taken as a cure for gonorrhoea. A decoction of the root bark is used as a purgative and emetic. The young fruits, in particular the husks, are used as fish poison. In New Guinea the juice of the fruit is taken as a cure for toothache.

Properties

The latex, copious in unripe fruits and less abundant in other parts of the plant, is reported poisonous. Aesculetin, a substance poisonous to fish, has been isolated from the fruit. In the seeds 50-60% of a greenish-yellow oil is present.

Botany

• A small tree up to 18 m tall, usually less than 10 m, glabrous and containing latex; trunk short, thorny, not buttressed, with greyish, shallowly fissured bark; crown bushy, usually with upright branches and more or less drooping twigs.
• Leaves (narrowly) elliptic or lanceolate, 5-12 cm × 2-4 cm, finely crenate or serrate, apex tapered, with 2 small glands at the base of the blade; blades glossy green above, yellowish-green beneath, old leaves yellow; petiole 7-20 mm long, reddish.
• Flowers in (apparently) terminal, ca. 5 cm long spikes; male flowers many, with 3 stamens; female flowers solitary (or sometimes 2) at the base of the spike, with 3 long styles.
• Fruit a globose, woody capsule, 2.5-3 cm diameter, dark grey-brown to almost black, 3-seeded.

In habit and in the leaves, this species resembles a willow.

In most literature mock-willow is found under the name Sapium indicum. In fact, the distinction between the genera Sapium P. Browne and Excoecaria L. is not clear, and botanists hold different views. However, in 1981 Airy Shaw placed the species in Excoecaria. It is possible that after stabilization of the nomenclature in the section Hippomaneae, the correct name of this taxon will become Shirakiopsis indica (Willd.) Esser.

Ecology

Mock-willow is usually found in wet places along rivers and near tidal marshes, but also in evergreen lowland forest, up to 250 m. Locally it is common.

Prospects

The qualities of this species as dye, vegetable, condiment and medicine need better investigation. It might be an interesting species for lands too wet for other crops.

Literature

• [31] Airy Shaw, H.K., 1972. The Euphorbiaceae of Siam. Kew Bulletin 26: 191—363.
• [32] Airy Shaw, H.K., 1975. The Euphorbiaceae of Borneo. Kew Bulletin Additional Series IV. Her Majesty's Stationery Office, London, United Kingdom. 245 pp.
• [33] Airy Shaw, H.K., 1980. The Euphorbiaceae of New Guinea. Kew Bulletin Additional Series VIII. Her Majesty's Stationery Office, London, United Kingdom. 243 pp.
• [34] Airy Shaw, H.K., 1981. The Euphorbiaceae of Sumatra. Kew Bulletin 36: 239—374.
• [135] Burkill, I.H., 1966. A dictionary of the economic products of the Malay Peninsula. Revised reprint. 2 volumes. Ministry of Agriculture and Co-operatives, Kuala Lumpur, Malaysia. Vol. 1 (A—H) pp. 1—1240, Vol. 2 (I—Z) pp. 1241—2444.
• Chadha, Y.R. (Editor), 1972. The wealth of India. Raw materials. Vol. 9. Publications & Information Directorate, Council of Scientific and Industrial Research, New Delhi. p. 229.
• Corner, E.J.H., 1988. Wayside trees of Malaya. 3rd ed. Vol. 1. The Malayan Nature Society. United Selangor Press, Kuala Lumpur. pp. 312—313.
• [277] Edwards, M.C., Taylor, S.E., Williamson, E.M. & Evans, F.J., 1983. New phorbol and deoxyphorbol esters: isolation and relative potencies in inducing platelet aggregation and erythema of skin. Acta Pharmacologica et Toxicologica 53(3): 177—187.
• [288] Esser, H.-J., 1999. A partial revision of the Hippomaneae (Euphorbiaceae) in Malesia. Blumea 44(1): 149—215.
• [602] Lemmens, R.H.M.J. & Wulijarni-Soetjipto, N. (Editors), 1991. Plant Resources of South-East Asia No 3. Dye and tannin-producing plants. Pudoc, Wageningen, the Netherlands. 196 pp.
• [664] McLean, J.R., Plant, M., Lecuyer, D.W., Davidson, C. & Truong, J., 1995. Sapintoxin D is a weak tumour promoter in sencar mouse skin. Journal of Pharmacy and Pharmacology 47(3): 263.
• [788] Pételot, A., 1952—1954. Les plantes médicinales du Cambodge, du Laos et du Vietnam [The medicinal plants of Cambodia, Laos and Vietnam]. 4 volumes. Centre National de Recherches Scientifiques et Techniques, Saigon, Vietnam.
• [995] Taylor, S.E., Evans, F.J., Gafur, M.A. & Choudhury, A.K., 1981. Sapintoxin D, a new phorbol ester from Sapium indicum. Journal of Natural Products 44(6): 729—731.
• [996] Taylor, S.E., Gafur, M.A., Choudhury, A.K. & Evans, F.J., 1982. Sapatoxins, aliphatic ester tigliane diterpenes from Sapium indicum. Phytochemistry 21(2): 405—407.
• [1008] Tomlinson, P.B., 1986. The botany of mangroves. Cambridge University Press, Cambridge, United Kingdom, New York, United States & Melbourne Australia. 413 pp.
• Whitmore, T.C., 1973. Tree flora of Malaysia, a manual for foresters. Vol. 2. Longman, London. pp. 128—129.

Main genus page

• Excoecaria (Medicinal plants)
• Excoecaria (Timbers)

Authors

• J.L.C.H. van Valkenburg
• Purwaningsih