Yam

Dioscorea deltoidea

Physical Characteristics

Dioscorea deltoidea is a PERENNIAL CLIMBER growing to 3 m (9ft 10in). It is in flower from September to October. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required).. The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

E. Asia - Himalayas from Kashmir and Punjab eastwards to Nepal and China.

Habitats

Woodland Garden Sunny Edge; Cultivated Beds;

Edible Uses

Edible Parts: Root Edible Uses: Tuber - cooked[2, 177]. A slightly bitter flavour, it is usually boiled with some wood ash in order to remove the bitterness[272]. Some caution is advised. See notes below on other uses of the root and above on toxicity.

Medicinal Uses

Contraceptive Miscellany Parasiticide The juice of the root tuber istaken in the evening in the treatment of roundworm[272]. It is also used to alleviate constipation[272]. The roots of most, if not all, members of this genus, contains diosgenin[222, 240]. 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[222]. The roots of this species contain an average of 4.8% diosgenin[240].

Known Hazards

Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves[174].