Cao Dou Kou

Alpinia katsumadai, Katsumada's galangal, is a robust rhizomatous perennial herb of the family Zingiberaceae native to moist forest understorey in southern China (especially Hainan and Guangxi) and northern Vietnam. The fragrant, knotted, branching rhizome gives rise to clumped leafy pseudostems 1.5-3 m tall formed by the overlapping leaf sheaths, bearing alternate, oblong-lanceolate leaves 30-65 cm long and 6-10 cm wide, glabrous and bright green. The terminal, erect, conical raceme 20-30 cm long carries showy white flowers about 3 cm long with a distinctive yellow labellum streaked with red-purple, subtended by deciduous coloured bracts. The fruit is a globose, faintly ribbed, yellowish-brown capsule 1.5-3 cm across containing a tightly packed mass of polygonal greyish-brown aromatic seeds with a pungent, slightly bitter, warming, cardamom-like flavour, harvested when the capsules begin to split.