Dioscorea deltoidea
Yam
a perennial woody member of the Dioscorea genus in the family Dioscoreaceae.
Taxonomy and growth
- Family
- Dioscoreaceae
- Genus
- Dioscorea
- Life cycle
- perennial
- Woodiness
- woody
- Fertility
- self sterile
- Flower type
- dioecious
Uses
Toxicity
Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.
This section contains historical Plants For A Future notes marked noncommercial.
Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves[3].
Edible uses
This section contains historical Plants For A Future notes marked noncommercial.
Tuber - cooked[6][5]. A slightly bitter flavour, it is usually boiled with some wood ash in order to remove the bitterness[12]. Some caution is advised. See notes below on other uses of the root and above on toxicity.
- Plant part
- Root
Medicinal uses
Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.
This section contains historical Plants For A Future notes marked noncommercial.
The juice of the root tuber istaken in the evening in the treatment of roundworm[12]. It is also used to alleviate constipation[12]. The roots of most, if not all, members of this genus, contains diosgenin[9][10]. 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[9]. The roots of this species contain an average of 4.8% diosgenin[10].
- Product or use
- Contraceptive
- Product or use
- Miscellany
Material uses
This section contains historical Plants For A Future notes marked noncommercial.
A soap is obtained from the tuber[2]. This soap is due to the presence of poisonous saponins in the root[240, K]. The soap is also used as a body wash to kill lice[2][10].
- Product or use
- Parasiticide
- Product or use
- Soap
Ecology and functions
- Ecosystem niche
- Climber
Environment
- Range
- E. Asia - Himalayas from Kashmir and Punjab eastwards to Nepal and China.
- Habitat
- Forests and humus-rich soils, 1700 - 2800 metres in Kashmir[2]. Broad-leaved forests and scrub forests at elevations of 2000 - 3100 metres in western China[11].
- Light
- full sun
- Shade tolerance
- light shade
- Water
- moderate
- Soil textures
- sandy, loamy, clay
- Soil pH
- acid, neutral, alkaline
- Drainage
- well drained
- Tolerates Nutritionally Poor Soil
- No
- Drought
- intolerant
Propagation
This section contains historical Plants For A Future notes marked noncommercial.
Seed - sow March to April in a sunny position in a warm greenhouse and only just cover. It germinates in 1 - 3 weeks at 20°c[4]. 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[13]. Division in the dormant season, never when in growth[1]. 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[K]. 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[K].
Cultivation
This section contains historical Plants For A Future notes marked noncommercial.
We have very little information on this species and do not know if it will be hardy in Britain. It is unlikely to succeed in any but the mildest areas. It is cultivated for its edible root in India[6]. The following notes are based on the general needs of the genus. Easily grown in a fertile well-drained soil in a sunny position or light shade[7]. Prefers a rich light soil[1]. Plants produce tubercles (small tubers that are formed in the leaf axils of the stems), and can be propagated by this means[K]. A climbing plant that supports itself by twining around the branches of other plants[8]. Dioecious. Male and female plants must be grown if seed is required.
References
F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00
Singh. Dr. G. and Kachroo. Prof. Dr. P. Forest Flora of Srinagar. Bishen Singh Mahendra Pal Singh 1976-00-00
Kariyone. T. Atlas of Medicinal Plants.
Bird. R. (Editor) Focus on Plants. Volume 5. (formerly 'Growing from seed') Thompson and Morgan. 1991-00-00
Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 1984-00-00 ISBN 3874292169
Hedrick. U. P. Sturtevant's Edible Plants of the World. Dover Publications 1972-00-00 ISBN 0-486-20459-6
Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5
Grey-Wilson. C. & Matthews. V. Gardening on Walls Collins 1983-00-00 ISBN 0-00-219220-0
Foster. S. & Duke. J. A. A Field Guide to Medicinal Plants. Eastern and Central N. America. Houghton Mifflin Co. 1990-00-00 ISBN 0395467225
Chopra. R. N., Nayar. S. L. and Chopra. I. C. Glossary of Indian Medicinal Plants (Including the Supplement). Council of Scientific and Industrial Research, New Delhi. 1986-00-00
Flora of China 1994-00-00 http://flora.huh.harvard.edu/china/
Manandhar. N. P. Plants and People of Nepal Timber Press. Oregon. 2002-00-00 ISBN 0-88192-527-6
Thompson. B. The Gardener's Assistant. Blackie and Son. 1878-00-00