Dioscorea elephantipes Origin and Habitat: Cape of Good Hope, Southern Africa ( including the Clanwilliam District of the Western Cape and the Graaf-Reinet, Willowmore and Uniondale Districts of the Eastern Cape).
Habitat and ecology: This species is appears to have a wide tolerance of growing habitats, growing in weathered rock, on dry, stony slopes, under the protection of karroid bushes. Pollination is done by bees and bumble bees. The plant is adapted to growing in areas with seasonal rainfall, by going dormant in the dry season. In its natural environment it rests during the hot dry summer. Dioscorea elephantipes grows in the winter and the spring months. The above ground caudex is protected by elephantine bark while it rests. It is used to extreme heat (above 40°C), but it can also take low temperatures (-4°C).
Dioscorea elephantipes Description: The elephant foot, Dioscorea elephantipes, is a perennial deciduous caudiciform vine belonging to the monocot yam family (Dioscoreaceae). The enlarged, exposed tuberous base is a water-storing organ, called a caudex . The caudex most often reaches a diameter of 60-90 cm, but sometimes 3 (or more) meter and is covered in tough armor-like plates. It produces a seasonal clinging growth up to 6 metres long. The leaves are heart-shaped. It bears small insignificant yellowish green flowers.
Derivation of specific name: elephantipes in Latin refers to the elephant-like appearance on the outer covering of the bark.
Caudex: The large and partially exposed tuberous stem is woody-looking, firm in texture but succulent within, and covered on the outside with thick greyish-brown bark that becomes deeply cracked into polygonal, superbly sculptured, prominent, polygonal corky plates with age, it can reach 3 (or more) m in diameter with a height of nearly 1 m above ground (but usually doesn’t exceed 1m in width), and a maximum weight estimated at 365 kg. The tubercle-covered tuber resembles an elephant’s foot or a tortoise shell.
Stems: Dioscorea elephantipes produces a seasonal (annual to semiperennial) slender, twining, glabrous, much branched vine from the top of the caudex. The vines reaches 2 to 6 m and grow rapidly during the growing season (from Autumn to Spring) but usually die back in the summer, leaving the caudex to survive the hot, dry season.
Leaves: Alternate, shortly petioled, suborbicular to heart shaped, rather broader than long, 2.5-5 nm broad, entire, moderately firm in texture, very glossy, bright green or glaucous, conspicuously mucronate. Remember it drops its leaves in late spring.