Cyathostemma micranthum (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Cyathostemma micranthum (A.DC.) J. Sinclair

Protologue: Gard. Bull. Sing. 14(2): 225 (1955).

Family: Annonaceae

Chromosome number: 2n= unknown

Synonyms

Uvaria micrantha (A.DC.) Hook.f. & Thomson (1855).

Vernacular names

• Malaysia: daun ekur bukit kampong, daun larak (Peninsular)
• Thailand: nom maeo (Prachuap Khiri Khan), namtao noi (Prachin Buri)
• Vietnam: kỳ kương, bù quả hoa nhỏ.

Origin and geographic distribution

C. micranthum is the most widely distributed Cyathostemma species. It occurs in the Andaman Islands, Burma (Myanmar), Indo-China, Thailand, throughout the Malesian region and northern Australia.

Uses

In Peninsular Malaysia a decoction of the leaves or roots is given as a protective medicine after childbirth. In Thailand the roots are ground with a small amount of water and applied topically to treat insect stings.

Properties

There is currently no information available on the phytochemistry and pharmacological activity of C. micranthum . The shikimic acid derivative cyathostemmine has been isolated from C. viridiflorum Griff. bark in Malaysia.

Botany

A liana up to 10(-15) m long; twigs initially pubescent, later glabrous, brownish-black and finely striate, lenticellate. Leaves alternate, simple and entire, oblong-elliptical, 2.5-8(-14) cm long, shortly cuneate to rounded at base, acuminate to acute at apex, thinly leathery, sparsely pubescent, pinnately veined with 8-15 pairs of indistinct veins; petiole 1.5-3 mm long; stipules absent. Inflorescence a subterminal monochasial cyme, later appearing extra-axillary or opposite due to continued sympodial growth, consisting of 2 flowers; peduncle woody, up to 3 mm long; bracts c. 5 mm long. Flowers bisexual, regular, 3-merous; pedicel up to 7(-10) mm long; sepals free, broadly ovate-rounded, c. 2.5 mm long; petals 6, free, ovate, 4-5 mm long, pubescent, greenish-yellow to red or brown; stamens numerous, with connective apex arching over and concealing anthers; carpels numerous, pubescent, style absent, stigma U-shaped. Fruit consisting of several stiped monocarps 12-20 mm × c. 10 mm, glabrous, yellow to red or black, 1-2(-4)-seeded.

Cyathostemma comprises 10 species, and is distributed from eastern India and southern China to northern Australia. It belongs to the tribe Uvarieae , and is closely related to, possibly even congeneric with, Uvaria . C. micranthum is distinguished from other Cyathostemma by its comparatively small leaves, small monocarps and terminal or extra-axillary inflorescence.

Ecology

C. micranthum occurs in forest and thickets at low altitudes.

Genetic resources

C. micranthum does not seem to be in danger of genetic erosion because of its wide distribution and seemingly wide ecological adaptability.

Prospects

The utilization of C. micranthum as a medicinal plant is unlikely to increase unless future research reveals interesting pharmacological properties.

Literature

121, 173, 947.

Other selected sources

587.

Main genus page

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Authors

R.H.M.J. Lemmens