Homalanthus populneus (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Homalanthus populneus (Geiseler) Pax

Protologue: Engl. & Prantl, Nat. Pflanzenfam. 3, 5: 96 (1890).

Family: Euphorbiaceae

Chromosome number: 2n= 36, but alson= recorded as 76.

• Omalanthus populneus (Geiseler) Pax (orthographic variant),
• Omalanthus leschenaultianus A.H.L. Jussieu (1824),
• Homalanthus populifolius (Reinw.) Hook.f. (1888), non Omalanthus populifolius Graham.

A.H.L. de Jussieu published the genus as Omalanthus. In the literature, Homalanthus is usually used, and has been conserved.

Omalanthus has been used in the Dyes and tannins volume of PROSEA and Homalanthus in the Medicinal plants volume.

• Mouse deer's poplar (En)
• Indonesia: tutup (general), tutup abang (Javanese), totop (Madura)
• Malaysia: ludahi, kayu mata buta darat (Peninsular)
• Philippines: malabinunga (Tagalog), balanti (Bisaya, Bikol)
• Thailand: mae mae (Narathiwat).

Peninsular Thailand, Peninsular Malaysia, Singapore, Sumatra, Java, the Lesser Sunda Islands, Borneo, the Philippines, Sulawesi, the Moluccas, to the Bismarck Archipelago.

In Sabah fruits are used for treating wounds. In Peninsular Malaysia heated leaves are applied to the abdomen to treat fever and after childbirth. The terminal buds of about 1 m high plants are reported to be eaten by women to induce abortion. The leaves are given to cattle as a vermifuge, but are reported to be poisonous, as is also the latex from other parts of the plant. Pounded leaves are used as a fish poison. A decoction of bark and leaves is used to dye rattan, matting, pandan handicrafts and cotton cloth black. The rattan, matting and pandan are often buried in the mud before or after being soaked in a boiled infusion of bark and leaves. The leaves serve for wrapping taro for cooking. The wood is sometimes used in houses, but it is soft and not durable. The wood is used as firewood. H. populneus may be suitable for afforestation on better soils, and the wood is suitable for pulp and paper production.

The watery latex is poisonous. The wood is white and soft. Fibres with simple pits, moderately long, ca. 1.25 mm. Vessel elements 0.5-1.3 mm long, with simple perforation plates; ray-vessel pits usually round, ovoid to elongated, and larger than the intervessel pittings.

• A small tree, up to 6(-10) m tall, glabrous and with watery latex; bark greyish and roughened; crown up to 18 cm in diameter, flattish with spreading branches.
• Leaves triangular-ovate to rhombic-ovate, not peltate, 3-12 cm × 2.5-10 cm, entire, base almost truncate with two small glands at the base of the blade, apex acuminate; blades glaucous beneath, withering yellow to reddish; petiole 2-7 cm long, reddish, glandless.
• Flowers in terminal, 10-25 cm long racemes; male flowers many, with 6-10 stamens; female flowers 2-8 at the base of the raceme, long-stalked, with 2 long stigmas; bracts of male flowers with a pair of glands slightly shorter than bracts, stamens (6-)8-10.
• Fruit a subglobose capsule, ca. 1 cm in diameter, two-lobed, not carinate, glaucous, with 2 cavities each containing a single black seed.

H. populneus occurs at edges of primary forest, in secondary forest, on roadsides, along streams and in waste land, up to 3000 m altitude. It is often one of the characteristic plants in recently cleared areas, and may occur gregariously.

Homalanthus populifolius Graham is a very closely related species from Australia (Queensland, New South Wales), and is rarely found on Woodlark Island and the Louisiade Archipelago. This species is often confused with H. populneus, and sometimes cultivated in botanical gardens. Another closely related species is Homalanthus novoguineensis (Warb.) Lauterb. & K. Schumann, found from the Moluccas, Tanimbar Islands and Timor to the Bismarck Archipelago, Solomon Islands and Australia (Queensland). Homalanthus beguinii J.J. Smith is endemic in the Moluccas, and used there in the same way as H. populneus.

O. populneus is locally common, especially in mountains in secondary forest and young regrowth; it is also found in lowlands in the undergrowth of primary forest and along rivers. It is recorded as growing on various types of soils.

Research in the Philippines indicates the wood characteristics are favourable for the production of pulp and paper. This use is perhaps more promising than the use as dye.

• Airy Shaw, H.K., 1968. New or noteworthy species of Homalanthus. Malesian and other Asiatic Euphorbiaceae. Kew Bulletin 21: 409-412.
• Corner, E.J.H., 1988. Wayside trees of Malaya. 3rd ed. Vol. 1. The Malayan Nature Society. United Selangor Press, Kuala Lumpur, Malaysia. p. 257.
• Tavita, Y.L. & Palisoc, J.G., 1979. Morphological characteristics of some Philippine hardwoods and other plant fibres. Forpride Digest 8(3): 31-47.
• Whitmore, T.C., 1973. Tree flora of Malaya, a manual for foresters. Vol. 2. Longman, London. p. 102.

121, 234, 542. medicinals

• ' medicinals

P.C. van Welzen (Medicinals)

Purwaningsih (Dyes and tannins)