Dendrolobium (PROSEA)
Introduction |
Dendrolobium (Wight & Arn.) Benth.
- Protologue: in Miquel, Pl. jungh.: 215 (1852).
- Family: Leguminosae
- Chromosome number: x= unknown; D. triangulare: 2n= 22
Major species
- Dendrolobium triangulare (Retz.) Schindler,
- D. umbellatum (L.) Benth.
Origin and geographic distribution
Dendrolobium comprises 18 species. The Indo-Malesian region is a major centre of diversity with 8 species occurring, and 5 species are confined to the Australian region.
Uses
In general the uses of D. triangulare and D. umbellatum are linked to their attributed astringent properties. They are often used in the treatment of dysentery and diarrhoea. In Cambodia, a decoction of the roots of D. lanceolatum (Dunn) Schindler from China (Hainan), Thailand and Indo-China, is applied to treat rheumatism. In Thailand, a decoction of the roots is used in the treatment of kidney disorders with mucous, and yellow or red urine. A decoction of the roots of D. thorelii (Gagnep.) Schindler, from Thailand and Indo-China, is administered in Thailand to treat leucorrhoea.
Properties
Very little phytochemical and pharmacological information on Dendrolobium is available. The leaves of D. triangulare contain amines, for instance phenylethylamine and tyramine, and alkaloids such as hordenine, as well as general compounds such as tannins and flavonoids.
Hordenine is a phenylethylamine-type alkaloid, which has mild sympathomimetic effects (e.g. increase of blood pressure) similar to ephedrine. Furthermore, leaf extracts of D. triangulare displayed antibacterial effects against Escherichia coli and Shigella spp.
Description
- Shrubs or small trees up to 7 m tall.
- Leaves alternate, 3-foliolate or rarely 1-foliolate; petiole pulvinate; stipules present; leaflets variously shaped, lateral leaflets usually smaller than the terminal one, chartaceous to coriaceous, entire or undulate, with 1 stipel at the base of the lateral and 2 at the base of the terminal leaflets.
- Inflorescence axillary, subumbellate to shortly racemose or sometimes umbellate, densely-flowered, shortly pedunculate; primary bracts convex, scariose, striate, caducous; secondary bracts absent; bracteoles 2 at the base of the calyx.
- Flowers uniparous, papilionaceous, pedicellate; calyx usually campanulate, deeply 4-lobed; corolla white or pale yellow, standard broadly obovate or nearly orbicular, distinctly clawed, not auriculate; wings narrowly oblong, distinctly clawed, auriculate or not at the base, obtuse or rounded at the apex; keel petals long-clawed, distinctly auriculate or not; androecium monadelphous, stamens 10; ovary superior, sessile, (1-)2-8-ovuled.
- Pod indehiscent, incurved or straight, 1-8-jointed, usually not reticulate-veined. Seed transversely broadly oblong-ellipsoid to subquadrangular, rim distinctly arillate.
Growth and development
In Java, D. triangulare and D. umbellatum flower and fruit throughout the year. D. umbellatum shows nodulating ability.
Other botanical information
Dendrolobium has formerly been included in Desmodium, but it is a distinct natural group that can be distinguished by its axillary subumbellate inflorescences, uniparous flowers, monadelphous androecia, pollen characteristics, conspicuously long styles, thick corky or coriaceous pericarps and conspicuously rim-arillated seeds.
Ecology
The wide geographical range of D. umbellatum, its occurrence on seashores in combination with the thick-walled pod articles points to dispersal by water.
Propagation and planting
In D. triangulare, germination at temperatures below 20°C gradually decreases, and ceases altogether with exposure at 50°C. Pretreatment for 4 h at 70°C before transfer to ambient temperatures (24-29°C) gives a germination rate of 70-98%.
Handling after harvest
The leaves of D. triangulare are used fresh or can be cleaned and dried for storage. Decoctions, extracts or pills from dried extract can be prepared.
Genetic resources and breeding
CIAT (Colombia) has a total of 23 accessions of D. lanceolatum from China, Thailand and Vietnam, 31 accessions of D. triangulare from China, Thailand, Vietnam and Indonesia and 8 accessions of D. umbellatum from Vietnam, Indonesia and Papua New Guinea.
Prospects
Too little phytochemical and pharmacological information on Dendrolobium is available to fully evaluate its potential. More research is therefore needed.
Literature
- Chuakul, W., Saralamp, P., Paonil, W., Temsiririrkkul, R. & Clayton, T. (Editors), 1997. Medicinal plants of Thailand. Vol. II. Department of Pharmaceutical Botany, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand. pp. 95-96.
- Chu Van Tuong & Nguyen Quang Trung, 1984. "Ba che" tablets compared with ampixilin in the treatment of children cholera. Tong Bao Duoc Lieu 16 (3,4): 49-57. (in Vietnamese)
- Doan Thi Nhu, Nguyen Thuong Thuc, Do Huy Bich & Vu Thuy Huyen (Editors), 1991. Les plants médicinales au Vietnam. Livre 1. Médicine traditionelle et pharmacopée [The medicinal plants of Vietnam. Volume 1. Traditional medicine and pharmacopoeia]. Agence de Coopération Culturelle et Technique, Paris, France. p. 70.
- Dy Phon, P., Ohashi, H. & Vidal, J.E., 1994. Légumineuses - Desmodiées [Leguminosae (Fabaceae) Papilionoideae - Desmodieae]. In: Lescot, M., Vidal, J.E. & Vidal, Y. (Editors): Flore du Cambodge, du Laos et du Viêtnam [Flora of Cambodia, Laos and Vietnam]. Vol. 27. Muséum National d'Histoire Naturelle, Paris, France. pp. 8-27.
- Pedley, L., 1999. Desmodium Desv. (Fabaceae) and related genera in Australia: a taxonomic revision. Austrobaileya 5(2): 209-261.
- Smith, T.A., 1977. Phenethylamine and related compounds in plants. Phytochemistry 16(1): 9-18.
Selection of species
Authors
- N.O. Aguilar