Common Name:

General Information

Dioscorea tokoro is a perennial climbing plant growing from an irregularly branched, horizontal, spreading rhizome that is 7 - 10mm thick; it produces a number of twining stems up to 5 metres long, the stems twining to the left[].
The plant is harvested from the wild for local use as a food and medicine

Known Hazards

Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves[]. The root of this species is said to be poisonous raw.

Botanical References

,

Range

E. Asia -southern China, Japan, Korea.

Habitat

Thickets in lowland and foothills all over Japan[]. Mixed forests, bamboo forests, usually along ravine sides; at elevations from near sea level to 1,000 metres[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial Climber
Height	0.00 m
Self-fertile	No
Cultivation Status	Wild

Cultivation Details

Easily grown in a fertile well-drained soil in a sunny position or light shade[]. Prefers a rich light soil[].
Plants produce tubercles (small tubers that are formed in the leaf axils of the stems), and can be propagated by this means[].
A climbing plant that supports itself by twining around the branches of other plants[].
A dioecious species - both male and female forms must be grown if fruit and seed are required.

Edible Uses

Tuber - cooked[, ]. It should be soaked or boiled in lye before use since it is said to be poisonous raw[].

Medicinal

The roots are antirheumatic, antiseptic, antitussive and contraceptive[]. They are also used for desensitization. A decoction of the root is used in the treatment of arthritis, rheumatism and prostatitis[]. It is also a resolvent for blood clots[].

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[].

Other Uses

None known

Propagation

Seed - sow early spring to mid spring in a sunny position in a warm greenhouse and only just cover. It germinates in 1 - 3 weeks at 20°c[]. 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[].