Один из наиболее популярных и интересных молочаев. Растения легки в содержании, неприхотливы и быстро зацветают. Родина: пустыни Южной Африки.
Внешний вид: в молодом возрасте стебель имеет шаровидную форму, затем становится цилиндрическим и достигает 15-20 см высоты и около 10 см в диаметре. Окраска очень декоративна — зеленая, с многочисленными коричневыми полосками. С возрастом нижняя часть стебля становится коричневой. Ребер 7-10, плоских, с цветочными почками. На вершине стебля появляются желтые соцветия – циатии, цветки мелкие (цветение: апрель-июль).Euphorbia obesa is a peculiar, almost ball shaped dwarf succulent plant that resembles a stone. It can grow to 20 cm in height with a diameter of 9 cm. It is a single-stemmed, unbranched, firm-bodied plant. The stem is usually 8-angled and grooved, subglobose (almost spherical) in shape, elongating and becoming cylindric as it gets older. Younger plants have a rounded sea urchin-like shape. The rotund stem is mottled grey-green in colour with dull purple transverse bands. It has a tapering tap root.
The leaves are very rudimentary and soon drop off. Euphorbia obesa is dioecious, i.e. male and female flowers occur on different plants. All euphorbias have a complex floral arrangement that is termed a cyathium (a cup) and this is the unit of the inflorescence.
A cyathium contains many highly reduced male flowers or a single female flower. In Euphorbia obesa, the cyathia appear in summer, from "circular flowering eyes", situated along the tops of the angles, near the growing tip, on the stem. They are produced on fork-branched peduncles (flower stalks), have minute bracts and are finely hairy. The cyathia are cup-shaped to 3 mm in diameter, expanding in the female. The fruit is a slightly 3-angled capsule , up to 7 mm in diameter that explosively releases small rounded 2mm diameter mottled grey seeds when mature. The peduncles do not persist, and fall off after the seed has been dispersed.
Euphorbia obesa is a rare endemic of the Great Karoo, south of Graaff-Reinet in the Eastern Cape. Over-collecting by collectors and plant exporters almost resulted in the plant becoming extinct in the wild. Today it is protected by national (Nature Conservation) and international (CITES) legislation. The plants occur in karoo vegetation among Beaufort shale fragments, where they grow in full sun or in the partial shade provided by dwarf karoo shrubs. They are very well camouflaged and difficult to see. The habitat is very stony and hilly with summer rainfall ranging from 200-300 mm per annum, falling mainly in thunder showers. Summers are very hot: the average daily maximum about 26 degrees centigrade and the minimum about 11 degrees centigrade. Light frost occurs during the winter months.
Professor Peter Macowan (1830-1909), a botanist from Gill College in Somerset East, discovered Euphorbia obesa near Graaff-Reinet in 1897. He collected this peculiar ball shaped succulent plant and sent it to the Royal Botanical Gardens, Kew. It flowered in their succulent house in 1899 when a description was drawn up and the plant named by Joseph Dalton Hooker (1817-1911). Today it is one of the most sought after succulent plants of South Africa.
The genus Euphorbia was established by Linnaeus in 1753 and commemorates Euphorbus, the 1st century physician to King Juba II of Mauritania, who is thought to have used plants, such as euphorbias, as medicine. It is a large genus and consists of about 2000 species. Not all are succulent. Of the ± 270 species that occur in South Africa almost 200 (74%) are succulent. Euphorbias are widespread in southern Africa, ranging from the north to the south, east to west, from the coast to the high Drakensberg escarpment and Lesotho. They vary from dwarf plants a few centimetres high to large trees such as the naboom, Euphorbia ingens that can grow up to 15 m tall. Most succulent euphorbias are common in the semi-arid parts of South Africa. The Eastern Cape is especially rich in Euphorbia species. Most of these make splendid garden subjects and are excellent for the hot, dry garden. Euphorbias have a milky latex which is poisonous and is especially irritant to tender or cut skin and the eyes and all plants should be handled with care.