Costus speciosus (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Costus speciosus (Koenig) J.E. Smith

Family: Zingiberaceae

Synonyms

Banksia speciosa Koenig, Costus sericeus Blume, C. nepalensis Roscoe.

Vernacular names

• Crepe ginger, wild ginger, Malay ginger (En)
• Indonesia: tabar-tabar (Javanese), pacing (Sundanese), setawar (Sumatra)
• Malaysia: setawar, tawar, setengteng
• Philippines: tubong-usa (Bikol), tiuasi (Subanum)
• Cambodia: trâthôk
• Laos: 'üangz
• Thailand: uang-maina (general), uang-yai (southern), uang-phetma (central)
• Vietnam: củchóc, mía dò, dót dắng.

Distribution

Widespread from India throughout South-East Asia to Taiwan and Australia. Occasionally also cultivated and sometimes naturalized in other tropical areas, e.g. in southern America.

Uses

The tuberous rhizome is eaten in times of food scarcity; on dry weight basis it contains about 66% carbohydrates, but is rather fibrous. Tender shoots are eaten as a vegetable. The rhizomes and seeds contain diosgenin (1.25-3% on dry weight basis) and ß-sitosterol (sapogenins); the seeds also contain a sweet-smelling fatty oil. The juice from crushed leaves and young stems is used externally to treat eye and ear diseases, juice from fresh rhizomes is considered to be purgative. In Malaysia, C. speciosus is an important ceremonial plant, used as tonic, depurative and aphrodisiac. Rhizomes are eaten with betel against cough, and decoctions and bruised leaves are applied externally against skin diseases and fever. The saponins of the rhizome have significant anti-inflammatory and anti-arthritic activity.

Observations

Perennial, much-branching herb, 2-3 m tall, glabrous to variously hairy, with rhizome that can become tuberous. Leaves spirally arranged; sheath 4 cm long, blade oblanceolate-acuminate, up to 23 cm × 6 cm. Inflorescence an ellipsoid cluster of cincinni, about 10 cm × 5 cm, terminal on a leafy shoot; corolla tubular, ending in lobes, 5-6 cm long, pinkish white; labellum curved, trumpet-shaped, 6-7 cm × 8-10 cm, white. Fruit bright red, dehiscing loculicidally. Seed black with fleshy white aril. C. speciosus occurs in forest edges and similar half open, rather wet locations, not in full forest shade, up to 1000 m altitude. Propagation is possible from seed, pieces of rhizome and by tissue culture.

Selected sources

3, 9, 13, 19, 20, 25, 32, 35, 49, 52, 53, 64, 81, 82, 84, 93, 94.

Authors

L.E. Groen, J.S. Siemonsma & P.C.M. Jansen