Herb: Yam


Latin name: Dioscorea deltoidea


Family: Dioscoreaceae (Yam Family)



Medicinal use of Yam:

The juice of the root tuber istaken in the evening in the treatment of roundworm. It is also used to alleviate constipation. 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. The roots of this species contain an average of 4.8% diosgenin.

Description of the plant:



Plant:
Perennial Climber


Height:
3 m
(9 3/4 foot)

Flovering:
September
to October

Habitat of the herb:

Forests and humus-rich soils, 1700 - 2800 metres in Kashmir. Broad-leaved forests and scrub forests at elevations of 2000 - 3100 metres in western China.

Edible parts of Yam:

Tuber - cooked. A slightly bitter flavour, it is usually boiled with some wood ash in order to remove the bitterness. Some caution is advised. See notes below on other uses of the root and above on toxicity.

Other uses of the herb:

A soap is obtained from the tuber. This soap is due to the presence of poisonous saponins in the root. The soap is also used as a body wash to kill lice.

Propagation of Yam:

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 possibly 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 the herb:

Forests and humus-rich soils, 1700 - 2800 metres in Kashmir. Broad-leaved forests and scrub forests at elevations of 2000 - 3100 metres in western China.

Known hazards of Dioscorea deltoidea:

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

Plant information taken from the Plants For A Future.