homebanner homebanner homebanner homebanner homebanner homebanner
Dioscorea japonica - Thunb.
Common Name Glutinous Yam, Japanese yam
Family Dioscoreaceae
USDA hardiness Coming soon
Known Hazards Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves[174].
Habitats Wooded foothills[58]. Mixed forests and margins, scrub forests, herb communities, mountain slopes, valleys, along rivers and streams, roadsides; 100 - 1200 metres[266].
Range E. Asia - China, C. and S. Japan.
Edibility Rating  
Other Uses  
Weed Potential No
Medicinal Rating  
Moist Soil Full sun


Dioscorea japonica Glutinous Yam, Japanese yam

Dioscorea japonica Glutinous Yam, Japanese yam
Physical Characteristics
Dioscorea japonica is a PERENNIAL CLIMBER. It is in flower from Sep to October. The flowers are 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: acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It prefers moist soil.


Woodland Garden Sunny Edge; Cultivated Beds;
Edible Uses
Edible Parts: Leaves;  Root.
Edible Uses:

Tuber - cooked[174, 177, 179]. A very pleasant mild flavour with a floury texture, the roots can be eaten as a potato substitute[2]. The starch can be used as a binding agent for other foods[183]. Roots contain about 1.9% protein, 20% carbohydrate, 0.1% fat and 1% ash[179]. Leaf tips - cooked[183]. Tubercles - cooked[183].
Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.

Contraceptive;  Miscellany;  Tonic.

The tubers are prescribed in the treatment of diarrhoea, enteritis, enuresis and spermatorrhoea[218]. They are also dried and cut into shavings then used as a tonic[218]. 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].
Other Uses

None known
Cultivation details
We have very little information on this species and do not know if it will be hardy in Britain, though judging by its native range it could succeed outdoors at least in the mildest areas of this country. 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[200]. 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[219]. Dioecious. Male and female plants must be grown if seed is required.
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[175]. 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[37]. 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 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].
Other Names
Found In
Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

Conservation Status
IUCN Red List of Threatened Plants Status :
Related Plants
Plant Suppliers: Click here for a List

      You can download this page as a PDF

Expert comment
Botanical References
Links / References
For a list of references used on this page please go here
Readers comment
Chuck E.
link to scanned page of this book which contains the species Jan 20 2012 12:00AM
Internet Archive- Flora of Japan by Jisaburo Ohwi, p.314
QR Code

What's this?

This is a QR code (short for Quick Response) which gives fast-track access to our website pages. QR Codes are barcodes that can be read by mobile phone (smartphone) cameras. This QR Code is unique to this page. All plant pages have their own unique code. For more information about QR Codes click here.

1. Copy and print the QR code to a plant label, poster, book, website, magazines, newspaper etc and even t-shirts.
2. Smartphone users scan the QR Code which automatically takes them to the webpage the QR Code came from.
3. Smartphone users quickly have information on a plant directly for the pfaf.org website on their phone.
Add a comment/link

If you have important information about this plant that may help other users please add a comment or link below. Only comments or links that are felt to be directly relevant to a plant will be included. If you think a comment/link or information contained on this page is inaccurate or misleading we would welcome your feedback at admin@pfaf.org. If you have questions about a plant please use the Forum on this website as we do not have the resources to answer questions ourselves.

* Please note: the comments by website users are not necessarily those held by PFAF and may give misleading or inaccurate information.

Subject : Dioscorea japonica  

Plant Uses

Edible Uses
Medicinal Uses
Other Plant uses
Woodland Gardening
Why Perennial Plants?
Top Edible Plants
Top Medicinal Plants
Garden Design


Content Help
Support Us
Old Database Search
About Us
Sign In

PFAF Newsletter

Stay informed about PFAFs progress,
challenges and hopes by signing up for
our free email newsletter. You will receive
a range of benefits including:
* Important announcements and news
* Exclusive content not on the website
* Updates on new information &
functionality of the website & database

We will not sell or share your email address.
You can unsubscribe at anytime.