Dioscorea elephantipes or elephant’s foot yam is a vine with a remarkable tuber.
It is slow-growing. The tendrils appear mainly in winter but the growth cycle is quite erratic. Some plants have a rest period of a few weeks, others a few months.
This is an easy plant which can be grown in a greenhouse but also as an indoor plant on the windowsill. In the summer it may be kept outdoors.
It is suspected that Dioscorea hemicrypta would be part of Dioscorea elephantipes. The caudex and leaves are slightly different. This is currently being investigated.
Dioscorea elephantipes is a climbing plant which grows up to 1.5 m long.
The caudex or tuber has a diameter of up to 75 cm, sometimes up to 3 m wide and 1 m high. It is for the most part above ground. The skin of the tuber is gray-brown and hard, with thick slabs of cork that are similar to the plates of a turtle. With age the tuber looks somewhat like an elephant’s foot. The inner tissue is yellowish-white, opaque and brittle.
From this tuber appear branches in the winter that remain 10-14 months. In contrast to other Dioscorea, they twine only at the top. The stem is up to 90 cm long and 15 mm in diameter at the base, dark brown, hairless and branched.
The leaves are small, usually up to 3 cm wide and long. They are variable in shape, the base is rounded to shallow heart-shaped. The leaves are bluish with age and folding along the midrib when the plant lacks water to reduce water loss.
The plant is dioecious, male and female flowers are on separate plants. Male flowers are yellowish and worn on an inflorescence up to 8 cm long, which is present from November to February. The female flowers are yellow-green, up to 8 cm long and up to 15 flowers with mustard-colored tepals.
The fruit is a dry, 3-winged capsule 2 cm long and 1.8 cm in diameter. The capsules are light brown with dark diagonal markings and ripen from April to October. Each capsule carries up to 6 light brown, apical-winged seeds.
Food: the tuber is very starchy and can be eaten, but only after prolonged boiling to remove toxins. It is only eaten in times of famine.
Medicinal: the tuber is very rich in saponins.
Elephant’s foot yam, Hottentot bread, turtle back
Dioscorea elephantopus, Dioscorea montana, Dioscorea testudinaria, Rhizemys elephantipes, Rhizemys montana, Tamus elephantipes, Testudinaria elephantipes, Testudinaria elephantipes f. montana, Testudinaria montana
Dioscorea: after the Greek physician and herbalist Dioscorides Pedanios, 1st century AD
Elephantipes: from the Latin elephantus (elephant) and pes, pedis (foot)
Rocky slopes in dry soil, at 150-1,200 m altitude
USDA zone 9-11
Very well drained substrate, half organic and half inorganic (Seramis, gravel, perlite)
Water reasonably well during growth period. Drastically reduce watering during resting period but never let it dry out completely.
Fertilize monthly, in the summer with higher N and lower K content fertilizer.
Use a clay pot, this reduces the risk of rot. The roots are shallow, so a shallow pot is sufficient. Take a pot which is just slightly larger than the diameter of the tuber.
When the plant enter its resting period, the stalks wither. They may be cut to just above the tuber.
Minimum 12-15 °C
- sow in spring in moist cactusmix
- 19-24 °C
- germination time: 21-36 days
- after 1 year, the caudex is approximately 1 cm in diameter and the seedling can be transplanted into individual pot