Gouania (PROSEA)
Introduction |
Gouania Jacq.
- Protologue: Select. stirp. amer. hist.: 263 (1763).
- Family: Rhamnaceae
- Chromosome number: x= unknown
Origin and geographic distribution
Gouania consists of some 50-70 species, and occurs throughout the tropics; in South-East Asia about 10 species occur.
Uses
Gouania is only little used in South-East Asian folk medicine, primarily as a poultice to treat sores, ulcers, burns and skin complaints.
Properties
Leaves and stems of G. leptostachya showed distinct antimicrobial activity against Staphylococcus aureus . The alkaloids present in bark and leaves of G. leptostachya have a tetanizing effect on toads. Saponins are present in numerous Gouania species, which may well explain the use to stupefy fish and as a soap substitute.
Botany
Unarmed climbing shrubs or lianas; branches often with circinnate tendrils. Leaves alternate, simple, ovate to cordate, entire or crenate, membranous to coriaceous, petiolate; stipules present. Inflorescence a terminal or axillary spike or raceme, sometimes arranged in panicles. Flowers bisexual or unisexual (polygamous), 5-merous; calyx funnel-shaped; petals free, small, shortly clawed; stamens before the petals; disk filling the calyx tube; ovary inferior, immersed in the disk, 3-celled; style 3-parted. Fruit a capsule, trigonous, 3-winged, crowned by the persistent calyx, splitting into 3 indehiscent, 1-seeded cocci. Seeds obovate, plano-convex; testa shining, horny; albumen thin.
In Java G. javanica flowers and fruits from May to October, whereas G. leptostachya can be found flowering and fruiting throughout the year.
Gouania in South-East Asia is in great need of revision. The status of G. tiliaefolia Lamk deserves more attention; it is not clear whether it should be united with G. leptostachya or not.
Ecology
Gouania species of medicinal importance are found in relatively open forest and forest fringes, often along rivers, at low to medium altitudes.
Genetic resources
The Gouania species treated here are relatively widespread and apparently adapted to disturbance. The risk of genetic erosion seems to be limited.
Prospects
Very little is known on the phytochemistry and pharmacological properties of Gouania . Further research is needed to corroborate its traditional use in poulticing.
Literature
62, 121, 927.
Selection of species
Authors
A.M. Aguinaldo