Pogostemon benghalensis (PROSEA)
Introduction |
Pogostemon benghalensis (Burm.f.) Kuntze
- Family: Labiatae
Synonyms
- Origanum benghalense Burm.f.,
- Pogostemon parviflorus Benth.,
- P. plectranthoides auct., non Desf.
Vernacular names
- Thailand: niam nguang chaang (central), om (northern).
Distribution
India, Sri Lanka, Nepal, Bangladesh, Burma (Myanmar), Thailand and China. It is also occasionally cultivated.
Uses
The leaves are used to distil a kind of patchouli oil which has an odour reminiscent of cedar wood. The oil is used as a stimulant and styptic. Fresh leaves are used to clean wounds and promote their healing. The flowers are a well known source of pollen and nectar for bees to produce panagol honey. Commercially, P. benghalensis is most important in India.
Observations
- Herb with strong, solid, angular stem.
- Leaves opposite; petiole 2.5 cm long; blade ovate, 13 cm × 6 cm, base cuneate, margin double dentate, apex acuminate.
- Inflorescence a verticillaster, arranged in a terminal false spike, about 7 cm long, at base branched into more than 2 lateral spikes.
- Calyx inflated, tubular, about 4 mm long, hairy outside, glabrous inside, with 5 ciliate teeth of about 1 mm length; corolla tubular, up to 8.7 mm long, 2-lipped, upper lip 3-lobed; stamens 4, inserted at different heights in the corolla tube, filaments 5-7 mm long.
- Fruit composed of 4 nutlets; nutlet obovoid, 1.2 mm long, finely punctate.
P. benghalensis occurs in open riverine forest, but is also cultivated in India. Besides an essential oil it contains an astringent resin, an alkaloid, and a yellow varnish of a slightly bitter taste. It much resembles P. plectranthoides Desf., but its narrower corolla tube and less crowded inflorescence are distinctive. It is worthwhile to investigate cultivation prospects for South-East Asia.
Selected sources
- Raza Bhatti, G. & Ingrouille, M., 1997. Systematics of Pogostemon (Labiatae). Bulletin of the Natural History Museum London (Botany) 27: 77-147.
- Weiss, E.A., 1997. Essential oil crops. CAB International, Wallingford, United Kingdom. 600 pp.
Authors
P.C.M. Jansen