Blechum pyramidatum (PROSEA)
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Introduction |
Blechum pyramidatum (Lamk) Urb.
- Protologue: Feddes Repert. 15: 323 (1918).
- Family: Acanthaceae
- Chromosome number: 2n= 34
Synonyms
Blechum brownei Juss. (1807).
Vernacular names
- Philippines: sapin-sapin, dayang (Tagalog), bamburia (Iloko).
Origin and geographic distribution
B. pyramidatum originates from tropical America, but has been introduced and is naturalized in southern Taiwan, the Philippines, and islands of the Pacific such as the Mariana Islands, the Caroline Islands and Western Samoa.
Uses
A decoction of the entire plant is used to treat blennorrhoea in the Philippines; the pounded leaves are used to heal wounds. In Costa Rica, a decoction of the plant is a popular remedy for dysentery, and in Cuba it is valued as a powerful diuretic. In Jamaica, a decoction is used in a stimulant bath, and to treat colds, whereas in Mexico it is considered a remedy for snakebites, chills and fever. In Panama, a decoction of the entire plant is used to treat vomiting.
Botany
An annual or short-lived, erect or ascending herb up to 50(-70) cm tall; stems often prostrate and rooting at lower nodes. Leaves decussately opposite, simple and entire, ovate, 3-10 cm × 2-5 cm, thin, obtuse or rounded at base, acute at apex, sparingly strigose above and nearly glabrous below; petiole up to 2.5 cm long; stipules absent. Inflorescence a dense terminal spike up to 6 cm long, with large foliaceous bracts c. 1.5 cm long, the margins conspicuously ciliate. Flowers solitary or in pairs in the axils of bracts, small, bisexual, each flower with 2 linear bracteoles; calyx 5-partite with linear segments; corolla gamopetalous, scarcely longer than bract, with slender tube and 5 subequal lobes contorted in bud, puberulent, white; stamens 4, didynamous, inserted above the middle of the corolla tube; ovary superior, 2-celled, style subulate. Fruit an ovoid capsule c. 5 mm long, puberulent, loculicidally 2-valved, after dehiscence the placentae rising elastically from the base of the fruit, many-seeded. Seeds orbicular, c. 1.5 mm in diameter.
Blechum consists of about 6 species and is native to tropical America. It should not be confused with Blechnum , which is a fern genus.
Ecology
B. pyramidatum is common in and around many towns at low altitude in the Philippines: in waste places, open thickets and on old walls. In tropical America, it is a weed of fields, shady waste places and moist thickets, up to 1400 m altitude. It is sometimes a troublesome weed, e.g. in taro ( Colocasia esculenta (L.) Schott) in Western Samoa.
Management Seeds of B. pyramidatum germinate at a temperature of 10-40°C, but the optimum is 20-35°C. There is no marked dormancy, and the seeds lose their germination capacity comparatively rapidly.
Genetic resources
B. pyramidatum occurs commonly in anthropogenic habitats and is consequently not easily liable to genetic erosion.
Prospects
It is not possible to give an indication of the medicinal prospects of B. pyramidatum because no information is available on pharmacological properties and phytochemistry. However, research seems worthwhile because of the medicinal uses in different parts of the world.
Literature
544, 760.
Other selected sources
117, 646.
Main genus page
Authors
R.H.M.J. Lemmens
