2875

12(3): Medicinal and poisonous plants 3

Sarcotheca laxa (Ridley) Knuth

Engl., Pflanzenr., Heft 95: 422 (1930).

OXALIDACEAE

2n = unknown

Connaropsis sericea Ridley (1920), Connaropsis simplicifolia Ridley (1922).

Malaysia: belimbing cherchek, belimbing hutan, gerinji (Peninsular).

Sarcotheca laxa occurs in Peninsular Malaysia and northern Sumatra.

On the east coast of Pahang, Peninsular Malaysia, Sarcotheca laxa roots are used for poulticing wounds. The sour fruits of Sarcotheca are added to stews, curries and cooked vegetables, and are said to be a good remedy against cough.

A shrub or small to medium-sized tree up to 23 m tall; bole up to 45 cm in diameter; young branches glabrous to densely ferruginous-tomentose. Leaves alternate, 1-foliolate, oblong to lanceolate, (5—)8—23 cm x (2—)3—8.5 cm, base broadly cuneate to truncate, apex acuminate to caudate, entire; petiole jointed, 0.5—2.5 cm long, upper part swollen and wrinkled; stipules absent. Inflorescence an axillary panicle, 1—3 together, up to 30 cm long, erect, pendent in fruit. Flowers bisexual, heterodistylous, 5-merous; sepals unequal, minute, connate at base; petals contorted, free at base but adhering above the claw and falling jointly, 4—7 mm x 1.3—2 mm, whitish to dark red; stamens 10, connate at base, longer and shorter ones alternating; ovary superior, 5-celled, styles free, long or short. Fruit a fleshy, 5-lobed berry 6—13 mm x 4—9 mm, red or black, with persistent sepals. Seeds flat, reddish. Seedling with epigeal germination; cotyledons leafy; hypocotyl elongated; first 2 leaves opposite, subsequent ones alternate.
Growth in Sarcotheca laxa is in flushes. Young leaves are deep violet. Flowering and fruiting occur almost throughout the year. Pollination is by insects (e.g. Xylocopa bees) and cross-pollination is regulated by the heterodistylous flowers. The fruits are eaten by bats, birds and monkeys which thus disperse the seeds.
Sarcotheca comprises 11 species occurring in Peninsular Malaysia, Sumatra, Borneo and Sulawesi. In the field, it can be confused with Rourea (Connaraceae), but the latter has free carpels, seeds with an aril, and dry, 1-celled and 1-seeded fruits.

Sarcotheca laxa is found scattered in primary and secondary forest, forest edges and swamps at low altitudes.

Although Sarcotheca laxa has a limited distribution, it does not appear to be threatened because it has a wide ecological amplitude.

As nothing is known with respect to the phytochemistry and pharmacological properties of Sarcotheca laxa further research is needed to support its traditional use or indicate its potential in herbal medicine.

[121]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.
[247]Flora Malesiana (various editors), 1950—. Foundation Flora Malesiana. Rijksherbarium/Hortus Botanicus, Leiden, the Netherlands.
[960]Veldkamp, J.F., 1994. A new variety of Sarcotheca laxa (Oxalidaceae) from Sumatra. Blumea 38(2): 459—460.

[883]Sosef, M.S.M., Hong, L.T. & Prawirohatmodjo, S. (Editors), 1998. Plant Resources of South-East Asia No 5(3). Timber trees: Lesser-known timbers. Backhuys Publishers, Leiden, the Netherlands. 859 pp.
[990]Whitmore, T.C. & Ng, F.S.P. (Editors), 1972—1989. Tree flora of Malaya. A manual for foresters. 2nd Edition. 4 volumes. Malayan Forest Records No 26. Longman Malaysia Sdn. Berhad, Kuala Lumpur & Petaling Jaya, Malaysia.

R.P. Escobin

Escobin, R.P., 2003. Sarcotheca laxa (Ridley) Knuth. In: Lemmens, R.H.M.J. and Bunyapraphatsara, N. (Editors): Plant Resources of South-East Asia No 12(3): Medicinal and poisonous plants 3. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea