Kuth

This genus of some 300 species of perennials is found in mountains of Europe, Asia, and N America. One or two species are occasionally seen in cultivation, but most of these thistle-like plants have no ornamental value. Saussurea costus (Costus, Kuth) has been used in both Chinese and Ayurvedic medicine for thousands of years. The roots have a pervasive scent, as indicated by the Chinese name, mu xiang, which means "wood fragrance"; the scent has been described as "reminiscent of violet, orris, and vetiver". Crops of costus are grown in China (mainly Guangdong Province) for the herb trade, and in N India as a source of oil for perfumery. Wild plants have been seriously over-collected; S. costus was placed under international protection as an endangered species in 1997. Saussurea was named after the Swiss philosopher and botanist Horace Benedict de Saussure (1740-99).

Perennial with a thick, tapering root, lyre-shaped, pinnate lower leaves, 30-40cm (12-16in) long, and about 30cm (12in) wide, and irregularly toothed upper leaves that clasp the stem. Purple, burdock-like flower heads, to 3.5cm (1½in) across, are produced in dense clusters or 2-3 in summer.

Common Name:	Kuth
Other Names:	Costus
Genus	Saussurea
Botanical Name:	Saussurea costus syn. S. lappa
Family:	Asteraceae
Native Location:	Himalayas.
Cultivation	Moist soil in sun or partial shade.
Propagation	By seed sown when ripe; by division in spring.
Harvest	Roots are lifted in autumn and spring, and dried for use in decoctions, liquid extracts, and powders, or processed for oil extraction.
Height:	2-3m (6-10ft)
Width:	1m (3ft)
Hardiness	Z10
Parts Used:	Roots (mu xiang), oil
Properties	A bitter, pungent, warming herb that relaxes spasms, lowers blood pressure, relieves pain, and has anti-bacterial effects. It regulates spleen and stomach energy.
Medicinal Uses:	Internally for abdominal distension and pain, chest pains due to liver problems, and jaundice, gall bladder pain, constipations associated with energy stagnation, and asthma. Used in Ayurvedic medicine for digestive problems, coughs, asthma, cholera, and as an alterative in skin diseases and rheumatism.
Culinary Uses:	Roots are sometimes used for flavoring.
Economic Uses:	Oil is used in commercial food flavoring; also used in perfumery.
Bibliography:	Encyclopedia of Herbs by Deni Bown Copyright © 1995, 2001 Dorling Kindersley Limited. pp 362-363