Greater galangal a plant in the ginger family, bears a rhizome used largely as an herb in Unani medicine and as a spice in Arab cuisine and Southeast Asian cookery. It is one of four plants known as "galangal", and is differentiated from the others with the common names lengkuas, Thai Ginger, and blue ginger.
Galangal is a robust, perennial, herbaceous plant growing in large clumps that can be 2 - 3.5 metres tall. It has a subterranean, creeping, copiously branched rhizome from which clumps of leaves are formed at intervals. The light red or pale yellow rhizomes are 2 - 4cm in diameter. Thai Ginger grows to a height of about 5 feet, the leaves being long, rather narrow blades, and the flowers, of curious formation, growing in a simple, terminal spike, the petals white, with deep-red veining distinguishing the lip-petal. The ranched pieces of rhizome are from 3.5-7.5 cm in length, and seldom more than 2 cm thick. They are cut while fresh, and the pieces are usually cylindrical, marked at short intervals by narrow, whitish, somewhat raised rings, which are the scars left by former leaves. They are dark reddish-brown externally, and the section shows a dark centre surrounded by a wider, paler layer, which be comes darker in drying. Their odour is aromatic, and their taste pungent and spicy. Galanga is a very popular spice in whole South East Asia and especially typical for the cuisine of Thailand. It is also known and used in Malaysia, Indonesia, Cambodia, Vietnam and Southern China.
The rhizome has a wide range of applications in traditional medicine. It is especially valued for its stimulating effect upon the digestive system, being used to treat conditions such as indigestion, colic and dysentery, whilst it is also used in the treatment of skin diseases, enlarged spleen, respiratory diseases, cancers of mouth and stomach, for treatment of systemic infections, cholera, and after childbirth. It is aphrodisiac, aromatic, bitter, digestive, expectorant, pungent herb that stimulates the digestive system.