''Euphorbia tuberosa'', commonly known as '"milkball/melkbol"' or '"wilderamenas"', is a variable geophytic plant of the family

Euphorbiaceae Euphorbiaceae, the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as ''Euphorbia paralias'', are herbs, but some, e ...

, indigenous to the western parts 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 countri ...

Description

A highly variable species, that has a tuberous underground caudex. Its deciduous leaves are grey-green, often with soft, fine hair. The leaf shape is lanceolate-to-oblong. Below the leaves' stalks they become narrower. The leaf margins are wavy or crisped, and usually curved upwards. It is dioecious and its yellow-green 5mm flowers (cyathia) appear over the Winter, on short (1–5 cm), trailing peduncles.

Related species

This species is closely related to '' Euphorbia ecklonii'', an

Overberg __NOTOC__ Overberg is a region in South Africa to the east of Cape Town beyond the Hottentots-Holland mountains. It lies along the Western Cape Province's south coast between the Cape Peninsula and the region known as the Garden Route in the e ...

species, which has wider leathery leaves that lie flat on the ground. It is also closely related to '' Euphorbia silenifolia'', which however has slender, linear, grass-like leaves. A more gracile form of ''Euphorbia tuberosa'' is sometimes treated as a separate species, ''Euphorbia crispa'' (Haw.) Sweet, distinguished by its very narrow leaves, which also have more strongly wavy/crisped margins and a more prominent midrib.

Distribution and habitat

''Euphorbia tuberosa'' is indigenous to the western, winter-rainfall (dry summer) regions of

, from

Namaqualand Namaqualand (khoekhoe: "Nama-kwa" meaning Nama Khoe people's land) is an arid region of Namibia and South Africa, extending along the west coast over and covering a total area of . It is divided by the lower course of the Orange River into ...

in the north, to

Cape Town Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest ...

in the south. In the

Little Karoo The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe !Orakobab or Khoemana word ''ǃ’Aukarob'' "Hardveld") is a semi-desert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its ext ...

region, it extends eastwards as far as the town of

Matjiesfontein Matjiesfontein is a settlement in Central Karoo District Municipality in the Western Cape province of South Africa. History The original inhabitants of the region were the Khoikhoi herders and the San hunter gatherers. Following the arrival o ...

. In the

region, it occurs around the town of Napier, and extends eastwards as far as the town of Riversdale. Its habitat is usually rocky or sandy soils in exposed areas of

renosterveld Renosterveld is a term used for one of the major plant communities and vegetation types of the Cape Floristic Region (Cape Floral Kingdom) which is located in southwestern and southeastern South Africa, in southernmost Africa. It is an ecoregion ...

fynbos Fynbos (; meaning fine plants) is a small belt of natural shrubland or heathland vegetation located in the Western Cape and Eastern Cape provinces of South Africa. This area is predominantly coastal and mountainous, with a Mediterranean clim ...

or succulent karoo vegetation.''E.tuberosa'' distribution - SANBI Redlist
/ref>

References

tuberosa Renosterveld Dioecious plants {{Euphorbia-stub