Microglossa pyrifolia (PROSEA)
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Introduction |
Microglossa pyrifolia (Lamk) O. Kuntze
- Protologue: Revis. gen. pl. 1 : 353 (1891).
- Family: Compositae
- Chromosome number: 2n= 18
Synonyms
Conyza pyrifolia Lamk (1786), Microglossa volubilis DC. (1836).
Vernacular names
- Papua New Guinea: pundari (Awala, Northern Province), goho (Buang, Morobe Province)
- Philippines: hugas (Bukidnon), maniak (Lanao), saroka (Bagobo)
- Thailand: khaa bia (north-eastern), tonghung, tonghong (northern)
- Vietnam: tiểu thiệt.
Origin and geographic distribution
M. pyrifolia is found in Africa and tropical Asia; it occurs throughout South-East Asia.
Uses
In Peninsular Malaysia a root decoction of M. pyrifolia is given to treat stomach-ache, and a leaf decoction to treat colds. In Papua New Guinea leaf sap is sprinkled on ulcers, which are subsequently covered by the crushed leaf. The vapour emitted from heated leaves is blown over spear wounds and sore eyes. In Africa emetic, purgative and diuretic properties are ascribed to the plant, when taken orally. Apparently the effects are dose-dependent because leaves are considered toxic and sap is said to be irritant to mucous membranes. A leaf infusion may be drunk as a vermifuge, and the plant is used to relieve oedemas, various stomach complaints and urethral obstructions. Various parts and preparations are used as a bath, taken orally, or externally applied as a febrifuge. A bath is credited with sedative action, and used to remedy insanity, epilepsy, and fits in children. A leaf poultice may be applied to inflammations, or rubbed on the chest to relieve pulmonary troubles. The powdered root is locally used as a snuff to relieve colds or as a local anodyne. Eye drops are made from leaf sap or sap from young roots to treat various eye troubles, e.g. ophthalmia.
Properties
Phytochemical analysis of leafy material of M. pyrifolia from Ivory Coast revealed the presence of traces of alkaloids, steroids and a strong haemolitic substance. Extracts of roots, stems, leaves and flowers have shown a weak insecticidal activity. Essential oil from the leaves of Cameroonian origin primarily consisted of (E)-β-farnesene (c. 75%) and β-caryophyllene (c. 13%). Acetylated aurone glucosides and acetylenic glucosides have been isolated from the leaves of plants collected in Papua New Guinea. One of these acetylenic glucosides (2-β-D-glucopyranosyloxy-1-hydroxy-trideca-3,5,7,9,11-pentayne) showed moderate antimicrobial activity, especially against Pseudomonas aeruginosa and Staphylococcus aureus . The following compounds were isolated from the petroleum ether/diethyl ether (1:1) extract: γ-cadinene, caryophyllene, dihydroxycaryophyllenepoxide, β-eudesmol, β-sitosterol, stigmasterol, β-amyrin and β-lupeol.
Botany
A scandent shrub up to 6 m tall; branches often climbing, terete, finely ribbed. Leaves alternate, simple, ovate-elliptical, 2-10 cm × 1.5-7 cm, base obtusely cuneate, apex acuminate, entire or with a few coarse teeth; petiole up to 2 cm long, widened at the base; stipules absent. Inflorescence a small, campanulate to funnel-shaped head 3-5 mm in diameter, many-flowered, numerous together arranged in a lax terminal corymb; peduncle 2-10 mm long; involucral bracts 3-4-seriate, lanceolate, 0.5-5 mm long, with an acute or obtuse, fringed top, broadly pellucid-margined. Flowers ligulate at margin of head, tubular at centre, c. 5 mm long; marginal flowers female, slender, whitish, glandular; disk flowers bisexual, yellow, glandular; stamens 5, forming a tube; ovary inferior, 1-celled, style with 2 short arms. Fruit a small obovoid somewhat compressed achene c. 1 mm long, 4-5-ribbed, pubescent and minutely glandular; pappus 1-seriate, consisting of many dentate hairs 4-5 mm long.
Microglossa consists of 10 species, and occurs in Africa, Madagascar, the Mascarene Islands and tropical Asia. It seems to be related to Conyza and Erigeron .
Ecology
In South-East Asia M. pyrifolia is found in open forest and forest margins at 500-1700 m altitude.
Genetic resources
M. pyrifolia is widespread and also commonly encountered in disturbed habitats, and is not threatened by genetic erosion.
Prospects
The antimicrobial activity of some of its compounds, in connection with its widespread medicinal use as an antiseptic, warrants further research on the pharmacological properties of M. pyrifolia .
Literature
120, 121, 350, 360, 794, 801.
Other selected sources
62, 112, 347, 511, 802.
Main genus page
Authors
J.L.C.H. van Valkenburg
