Herb: Glutinous Yam


Latin name: Dioscorea japonica


Family: Dioscoreaceae (Yam Family)



Medicinal use of Glutinous Yam:

The tubers are prescribed in the treatment of diarrhoea, enteritis, enuresis and spermatorrhoea. They are also dried and cut into shavings then used as a tonic. The roots of most, if not all, members of this genus, contains diosgenin. This is widely used in modern medicine in order to manufacture progesterone and other steroid drugs. These are used as contraceptives and in the treatment of various disorders of the genitary organs as well as in a host of other diseases such as asthma and arthritis.

Description of the plant:



Plant:
Perennial Climber


Flovering:
September
to October

Habitat of the herb:

Wooded foothills. Mixed forests and margins, scrub forests, herb communities, mountain slopes, valleys, along rivers and streams, roadsides, 100 - 1200 metres.

Edible parts of Glutinous Yam:

Tuber - cooked. A very pleasant mild flavour with a floury texture, the roots can be eaten as a potato substitute. The starch can be used as a binding agent for other foods. Roots contain about 1.9% protein, 20% carbohydrate, 0.1% fat and 1% ash. Leaf tips - cooked. Tubercles - cooked.

Propagation of the herb:

Seed - sow March to April in a sunny position in a warm greenhouse and only just cover. It germinates in 1 - 3 weeks at 20C. Prick out the seedlings as soon as they are large enough to handle and grow on in a greenhouse for their first year. Plant out in late spring as the plant comes into new growth. Basal stem cuttings in the summer. Division in the dormant season, never when in growth. The plant will often produce a number of shoots, the top 5 - 10 cm of the root below each shoot can be potted up to form a new plant whilst the lower part of the root can be eaten. Tubercles (baby tubers) are formed in the leaf axils. These are harvested in late summer and early autumn when about the size of a pea and coming away easily from the plant. They should be potted up immediately in individual pots in a greenhouse or cold frame. Plant out in early summer when in active growth.

Cultivation of Glutinous Yam:

Wooded foothills. Mixed forests and margins, scrub forests, herb communities, mountain slopes, valleys, along rivers and streams, roadsides, 100 - 1200 metres.

Known hazards of Dioscorea japonica:

Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves.

Plant information taken from the Plants For A Future.