Galangae Rhizoma. Galangal.
Synonyms.—Galangal Root; Lesser Galangal.
Galangal is the dried rhizome of Alpinia officinarum, Hance (N.O. Scitamineae), a flag-like plant cultivated in South-East China and on the neighbouring island of Hainan. It occurs in hard, branching, nearly cylindrical pieces, varying from 5 to 8 centimetres in length and from 10 to 15 millimetres in thickness, which are well characterised by their dull reddish-brown colour and by the paler frilled remains of cataphyllary leaves which encircle them at short intervals. The smoothed transverse section is generally paler than the exterior of the drug and exhibits a comparatively small stele surrounded by a wide cortex; in both cortex and stele numerous scattered deep red resin cells occur. It has an agreeable aroma and strongly pungent spicy taste. The rhizome of Alpinia officinarum should be carefully distinguished from that of the greater galangal, Alpinia Galanga, Willd., which is occasionally imported from Java, and may be distinguished by its larger size, orange-brown cork, and pale buff interior.
Constituents.—The aroma of galangal is due to a small quantity of volatile oil, and the pungency to an oily body, galangol. The drug also contains three tasteless, yellow, crystalline bodies, viz., kaempferid, galangin, and the monomethyl-ether of galangin. Alpinin, which has been described as a constituent of the drug, is said to be a mixture of kaempferid and galangin (dioxyflavanol).
Action and Uses.—Galangal is aromatic and carminative. It is used in the form of infusion or decoction (1 in 20) for flatulence and dyspepsia.