Alchornea (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Alchornea Sw.

Protologue: Prodr.: 6, 98 (1788).

Family: Euphorbiaceae

Chromosome number: x= 9

Alchornea is a pantropical genus of about 50 species. In South-East Asia, approximately 10 species occur, of which A. rugosa is the most widely distributed. Peninsular Malaysia and the Philippines are richest in species, each with about 5 species.

A decoction of leaves and roots of A. rugosa has been used in Malaysia to treat fever and ague. In Indonesia, there is mention of the fruits being applied as purgative. The roots and leaves of A. villosa have been prescribed in Malaysia to treat itch; this species is reportedly also used as an antidote for poisoning. In Indonesia, the leaf juice has been applied to cure fever and a poultice of leaves to treat headache. Leaves and fruits of A. parviflora and A. sicca are used in the Philippines as fish poison. The bark of A. villosa provides a good fibre; it is very tough.

A. cordifolia (Schumach. & Thonn.) Müll. Arg. is applied extensively in traditional medicine in Africa. It is used to treat cough, bronchial troubles, gonorrhoea, yaws, ulcers, rheumatic pains and fever. The root bark is an ingredient of traditional preparations to treat diarrhoea.

There are only very few reports on properties of Asian Alchornea . The 1:1 methanol-dichloromethane extract of an unidentified Alchornea species exhibited phorbal ester antagonist activity.

The tropical African A. cordifolia has a very broad spectrum of biological activities. An aqueous extract of the root bark exhibited antibacterial, anti-amoebic and antispasmodic activities; smooth muscle-relaxing flavonoids have been isolated from the leaves. A. floribunda Müll. Arg. from tropical Africa is reputed to have hallucinogenic properties.

Alkaloids are known to occur in bark and leaves of several Alchornea species, including A. rugosa . These are guanidin-derivatives of the alchornin type. The alkaloid alchorneine is found in A. floribunda .

Trees or shrubs, monoecious or dioecious. Leaves alternate, simple, crenate or dentate, short- to long-petiolate, stipulate, often also stipellate. Inflorescence a simple or compound raceme or spike, bracteate. Flowers unisexual, petals and disk absent; male flowers with a calyx of 2-5 segments and 3-8 stamens; female flowers with 4-8 free sepals and a (2-)3-locular ovary crowned by (2-)3 more or less free styles. Fruit a (2-)3-locular capsule, lobed or unlobed, smooth or muricate. Seedling with epigeal germination; hypocotyl elongate; cotyledons thin and leaf-like.

A. sicca flowers in the Philippines from March to June.

Alchornea occurs in lowland forest up to 1000 m altitude, often in secondary forest, forest edges, and also in scrub vegetation.

Alchornea often occurs in secondary forest and seems unlikely to be at risk of genetic erosion, the more so because it is not much sought after for timber or other products.

Although several South-East Asian Alchornea species are used medicinally, very little is known about their properties. The interesting properties of African species, about which much more information is available, warrant research on the Asiatic ones.

84, 121, 331, 334.

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R.H.M.J. Lemmens