Staurogyne (PROSEA)
Introduction |
Staurogyne Wallich
- Protologue: Pl. asiat. rar. 2: 80 (1831).
- Family: Acanthaceae
- Chromosome number: x= unknown
Origin and geographic distribution
Staurogyne comprises about 80 species and occurs in all tropical regions. The greatest diversity is found in South-East Asia with about 50 species; Peninsular Malaysia, Sumatra and Borneo are richest. Africa is least rich, with only 5 species.
Uses
Some applications of Staurogyne in traditional medicine in South-East Asia have been recorded: the roots and leaves are used as a diuretic and to treat diarrhoea, and whole plants to treat sore mouth and cough. In Sumatra (Riau Province) a maceration of an unidentified Staurogyne species crushed in water is rubbed over the body as a post-medication treatment for chronic fever. The leaves are sometimes eaten as a vegetable or chewed with betel.
Properties
Whole plants of an unidentified Staurogyne species from Sumatra showed slight in-vitro antimicrobial activity. Sweet-tasting oleanane-type triterpene glycosides named strogins, have been isolated from a water extract of S. merguensis leaves.
Botany
Small herbs or undershrubs. Leaves opposite, simple and entire, without cystoliths; petiole distinct, not connected by a transverse ridge; stipules absent. Inflorescence a terminal or seemingly axillary raceme, spike or head; upper bracts arranged spirally. Flowers bisexual, 5-merous; bracteoles similar to the calyx segments or narrower; calyx deeply 5-fid, with narrow, equal or unequal segments; corolla with tube gradually widened above the narrow base, lobes subequal, patent and flat; stamens 4, inserted below the middle of the corolla tube, didynamous, included; ovary superior, 2-celled, style with 2 stigmatic lobes. Fruit a narrowly ovoid or fusiform capsule, many-seeded. Seeds small, subglobose, reticulate-ribbed.
Staurogyne has been placed in the subfamily Nelsonioideae together with 4 other smaller genera. This group has been proposed for inclusion in the Scrophulariaceae , mainly based on fruit and seed characters, but this is not generally followed.
Ecology
Most Staurogyne species occur in lowland and lower montane forest, up to 1800 m altitude, often under shady and humid conditions, but some grow in more open and disturbed localities such as fallow rice fields, roadsides and open forest.
Genetic resources
In general, Staurogyne seems liable to genetic erosion due to the preference of most species for humid lowland forest, a type of habitat under increasing pressure.
Prospects
Information on phytochemistry and pharmacological properties of Staurogyne is almost completely lacking, which makes it impossible to judge its prospects as a medicinal plant. However, research seems useful because the recorded applications in local medicine (as a diuretic and antimicrobial) concur with several better investigated Acanthaceae that have a reputation as important medicinal plants. The sweetening activity of S. merguensis leaves is remarkable and might offer possibilities as an alternative for sugar.
Literature
295, 296.
Selection of species
Authors
Dodi Darmakusuma