Costus speciosus (Koening ex Retz.) J.E. Smith (Zingiberaceae)
(2n = 18,27,36)
Syn : Banksea speciosa J. Koening
Sanskrit names: Canda, Kemuka.
Vernacular names: Ben: Keu; Hin : Kebu, Keyu, Kusi; Kan : Chengaivakoshtu; Mal: Cannakilannu, Cannakkuvva, Narumeanna; Mar: Penva, Pushkarmula; Tam: Kostam, Kuiravam, Kottam; Tel: Chengaivakohtu.
Trade name: Keyu.
Traditional use: Rhizome: bitter, astringent, acrid, cooling, purgative, aphrodisiac, anthelmintic, depurative, febrifuge, expectorant and tonic, also beneficial in asthma, anaemia, bronchitis, leprosy, flatulence, constipation, fever, skin diseases and inflammation.
Modern use: in carcinogenic tumours.
Phytography : Succulent perennial herb with long leafy spirally twisted stems, 2-3 m high and horizontal rhizomes; leaves simple, spirally arranged, oblanceolate or oblong, glabrous above, silky pubescent beneath with broad leaf sheaths; flowers white, large, scented, in large terminal spikes; bracts bright red; fruits globose / ovoid capsules; seeds obovoid or semiglobose.
Phenology: Flowering: September-October; inflorescence globose of closely packed bracts.
Distribution: Throughout India; Pakistan and Bangladesh-in moist localities and in wastelands.
Ecology and cultivation: Hills above 800 m; moist places and wastelands also.
Chemical content: Root: rich in starch.