유포르비아 드레게아나-Euphorbia dregeana E.Mey. ex Boiss.

과명	Euphorbiaceae (대극과)	속명	Euphorbia (대극속)
전체학명	[정명] Euphorbia dregeana E.Mey. ex Boiss.	추천명	유포르비아 드레게아나
이명		외국명

2018-12-17	추천명 변경: 에우포르비아->유포르비아
	학명변경: 명명자변경 E.Mey. -> E.Mey. ex Boiss. 추천명변경: 드레게아나대극 -> 에우포르비아 드레게아나

Origin and Habitat: Euphorbia dregeana extends over wide areas of arid country from Tschaukaib in Namibia to the Richtersveld, Republic of South Africa (Northern Cape) and as far south as Komaggas in Namaqualand.
Habitat and ecology: It grows in rocky slopes on quartzitic, sandstone and gravel under a shallow reddish sandy-loamy topsoil, covering large areas of country in leaf succulent dwarf shrubland (Succulent Karoo). Species are mainly leaf succulent Aizoaceae, while larger plants of Aloe dichotoma, Aloe ramosissima, Euphorbia virosa, Sarcocaulon Burmanni, and Tylecodon paniculatum are prominent. Leaves may be formed only after good rains and be shed as soon as conditions become unfavourable. The the haustoria (the root of a parasitic plant )of the holoparasite Hydnora visseri (Hydnoraceae) are often found growing in rows attached to stems of Euphorbia dregeana. Another unusual parasitic plant, Hydnora triceps traverses the soil to parasitize its exclusive host, Euphorbia dregeana. The flowers of H. triceps apparently develop only underground and do not emerge from the soil.

Common Names include:
ENGLISH: Wolves’ milk (Latex), Elephant’s bush, Thickstem Milkbush
AFRIKAANS (Afrikaans): Soetmelkbos, Melkboom, Melk bos, Dikboudmelkbos, Bergmelkbos, Dikboud, Dikloot melkbos
GERMAN (Deutsch): Dreges Wolfsmilch

Description: Euphorbia dregeana is a finger-like succulent branching much at the base and above into a multitude of erect cylindrical green stems, radiating out to form a rounded bush 90-200 cm high and as much or more in diameter. The smooth, whitish-green stems topped with umbels of flowers make it an attractive plant. The flowers are yellow with two yellowish-green rounded petal-like lobes encircling the emerging six-sectioned seed capsule. It is the tallest and largest of the narrow-stemmed South African shrubby species with terete branches. The plant exudes the characteristic Euphorbia white latex, sometimes called wolves’ milk.
Stems: Spineless, smooth, cylindrical. Main stems 2-7,5 cm thick at the base, erect, branching; flowering branches terete, alternate, cylindric, 8-50 mm thick, with prominent markings all the way up where the small and short-lived leaves had fallen, very minutely puberulous on the young parts, becoming glabrous, or sometimes apparently quite glabrous, pale green to whitish-green, sometimes covered with a dry whitish exudation when dried.
Leaves: Alternate, rather rudimentary, only present on very young branchlets and early deciduous, sessile, or subsessile, 3-8 mm long, 1-6 mm broad, ovate or ovate-deltoid, acute or obtuse, channelled down the face, recurved, somewhat fleshy, minutely puberulous.
Inflorescences (Umbels or cymes): Clustered at brances tips or solitary, 3-6 mm in diameter, 3-rayed; rays 3-6 mm long, usually 1–3-times forked, but occasionally simple, minutely puberulous; bracts sessile, 4-7 mm long, 7-12 broad, nearly half-circular or rounded-subrhomboid when flattened out, obtuse or apiculate, concave, minutely puberulous on both sides; involucre sessile, 6-8 mm in diam. and about 1,5-2 mm deep, subglobose-cup-shaped, puberulous outside, glabrous within, with 5 glands overtopped by 5 erect subquadrate slightly fringed or very shortly and densely ciliate lobes; glands 2,5-3 mm long and 3-3,5 mm broad when flattened out, somewhat ovate-triangular or deltoid, with the part adnate to the involucre acute or subacute and the outer part subtruncate or crenulate or slightly lobed and wavy, incurved in dried specimens, but probably more or less deflexed or spreading and concave when alive, puberulous on the back, glabrous on the inner or upper surface. Syles 2-2,5 mm long, united for 1-1,5 mm of their length, with erect or recurved-spreading bifid (or entire?) tips.
Fruits (capsules): Sessile, 6 mm long, 8-9 mm in diameter, somewhat 6-angled, with 3 of the angles subacute, minutely puberulous. The capsule turns red when developed and brown later when it dries.
Seeds: 4 mm long, oblong, somewhat 4-angled, slightly pointed at one end, smooth, pale brown.

Euphorbia dregeana (llifle.com)

https://youtu.be/1_xqtjeewlI

https://youtu.be/7nfcbp5gdTc

 

https://youtu.be/HxUf7nYrRKw

https://youtu.be/7nfcbp5gdTc