''Dioscorea elephantipes'', the elephant's foot or Hottentot bread, is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...

in the genus ''Dioscorea'' of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Dioscoreaceae,

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and enterta ...

to the dry interior of

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...

Description

It is a

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, a ...

climber. It takes the name "elephant's foot" from the appearance of its large, partially buried,

tuber Tubers are a type of enlarged structure used as storage organs for nutrients in some plants. They are used for the plant's perennation (survival of the winter or dry months), to provide energy and nutrients for regrowth during the next growin ...

ous stem, which grows very slowly but often reaches a considerable size, often more than in circumference with a height of nearly above ground. It is rich in

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...

, whence the name Hottentot bread, and is covered on the outside with thick, hard, corky plates. It requires significant processing before being eaten t
remove toxic compounds
Primarily a winter grower, it develops slender,

leaf A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

y, climbing shoots with dark-spotted, greenish-yellow flowers in winter (May or June in habitat) The flowers are

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproducti ...

, with male or female flowers occurring on separate plants.

Distribution

Its natural habitat is the arid inland regions of the Cape, stretching from the centre of the Northern Cape (where it occurs around Springbok), south to the Clanwilliam & Cederberg area, and eastwards through the districts of Graaff Reinet, Uniondale and Willowmore, as far as Grahamstown. It was recentl
rediscovered
in a section of the Northern Cape Province by an expedition collecting seeds for the

Millennium Seed Bank Project The Millennium Seed Bank Partnership (MSBP or MSB), formerly known as the Millennium Seed Bank Project, is the largest ''ex situ'' plant conservation biology, conservation programme in the world coordinated by the Royal Botanic Gardens, Kew. Af ...

. In this area, it is most common on rocky north & east-facing slopes, in quartz or shale based soils.

Cultivation

This species is not difficult to cultivate, however it requires extremely coarse, well-drained soil, and sparse watering. Importantly, it is deciduous and loses its leaves in the summer. At this time it goes through a dry dormancy period. It has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (No ...

’s

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

Watering

This species indicates when it is requiring water, by the presence of green growth. From when a new growth appears from the caudex, it can receive regular watering, up until the growth withers and dies back. This is when the plant goes into its summer dormancy. Then watering should become more rare - until the next new growth appears. The cycle can be extremely unpredictable or erratic, but in most cases this results in a watering regime of wetter winter and spring, and a dry summer dormancy period.

Sun and shade

In nature, the caudex is usually in shade beneath thicket vegetation, and only the leafy tendrils reach up to the sunlight. Therefore, the caudex is sensitive to prolonged exposure to heat and full sunlight, and a dappled-sun or semi-shaded position is preferable. The green vine tendrils however, thrive if they are able to reach partial or full sunlight.PlantZAfrica.com article
/ref>

Soil

This plant grows naturally in brush on rocky slopes, so it requires extremely well-drained soil, with a large (at least 50%) mineral component.

Temperatures

In cultivation in

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

areas, ''D. elephantipes'' can tolerate temperatures to -4 °C in habitat.

Gallery

File:Discoreaceae - Testudinaria elephantipes.JPG, The large tuberous stem of ''Dioscorea elephantipes'' at the botanical garden of

Villa Durazzo-Pallavicini The Villa Durazzo-Pallavicini is a villa with notable 19th-century park in the English romantic style and a small botanical garden. The villa now houses the Museo di Archeologia Ligure, and is located at Via Pallavicini 13, immediately next to the ...

, Genova Pegli. File:Dioscorea elephantipes 03 ies.jpg, Leaves File:Testudinaria elephantipes montana1.jpg, Flowers''

References

* {{Taxonbar, from=Q3023510 Crops originating from Africa Root vegetables Flora of South Africa elephantipes Caudiciform plants House plants