Euphorbia cooperi (PROTA)
Euphorbia cooperi N.E.Br. ex A.Berger
- Protologue: Sukkul. Euphorb.: 83 (1906).
- Family: Euphorbiaceae
- Lesser candelabra tree, Transvaal candelabra tree (En).
Origin and geographic distribution
Euphorbia cooperi occurs from Tanzania south to north-eastern South Africa and Swaziland.
The latex is said to be one of the most poisonous of the Euphorbia spp., causing intense skin irritations and producing a burning sensation in the throat when standing next to bleeding plants. The latex may cause blindness if it comes into the eyes. It has a pungent, acrid smell. In South Africa the latex is boiled until black and then dried; the powder is applied to infected wounds. A root decoction, together with a root decoction of Euphorbia ingens E.Mey. ex Boiss., is applied as a dressing to treat paralysis. A bundle of grass soaked in the latex is attached to a stone and thrown into the water as fish poison.
Euphorbia cooperi is sometimes used to make fence poles. The flowers produce much nectar, but the honey, known as ‘noors honey’, causes a burning sensation in the mouth, which is intensified by drinking water. Euphorbia cooperi is planted as an ornamental in succulent gardens or rock gardens in South Africa and the United States.
Several diesters and triesters of 16-hydroxy-12-desoxyphorbol were isolated from the latex. The diterpene esters showed more or less pronounced irritation on mice ears, as well as tumour-promoting activity in vitro.
Monoecious, succulent, candelabriform small tree up to 6(–9) m tall, with abundant latex; bole stout, cylindrical, scarred from fallen branches; branches curved upwards, simple or sometimes branched near the apex, forming a flat-topped crown, branches 5–20 cm in diameter, deeply constricted at irregular intervals into oblong segments 10–50 cm long, (3–)4–6(–8)-angled, margins of angles wavy, with tubercles 8–25 mm apart; spine shields joined into a continuous horny margin 3–10 mm large, with 2 pairs of spines, 1 pair of stout spines up to 10 mm long, 1 (stipular) pair tiny, soon falling. Leaves at the end of branches, in 3–7 rows, sessile; stipules transformed into tiny spines; blade deltate, c. 1.5 mm × 1.5 mm, soon falling. Inflorescence an almost sessile, axillary cyme, crowded at the end of branches, 1–3 together in a horizontal line, consisting of clusters of flowers, each cluster called a ‘cyathium’, cyme branches 2; bracts 2, tiny; cyathia c. 4.5 mm × 8 mm, with a cup-shaped involucre, lobes c. 1.5 mm long, glands 5, transversely oblong, c. 1.5 mm × 4 mm, golden-yellow, each involucre containing 1 female flower surrounded by many male flowers. Flowers unisexual; male flowers sessile, perianth absent, with a single stamen; female flowers with pedicel 4–10 mm long in fruit, perianth shallowly 3-lobed, ovary superior, glabrous, 3-celled, styles 3, variably fused, 2–5.5 mm long, apex 2-fid. Fruit an obtusely to deeply 3-lobed capsule 6–10 mm × 10–13.5 mm, fleshy, green becoming red, 3-seeded. Seeds almost globose, 2.5–3.5 mm in diameter, pale greyish brown speckled with pale brown, smooth.
Other botanical information
Euphorbia comprises about 2000 species and has a worldwide distribution, with at least 750 occurring in continental Africa and about 150 species in Madagascar and the Indian Ocean islands. Euphorbia cooperi belongs to subgenus Euphorbia, section Euphorbia, a large group which is characterized by succulent, usually angular stems, stipules modified into small spines (or absent), a spine shield with an additional pair of spines (sometimes fused into a single spine), axillary inflorescences and seeds without a caruncle. Euphorbia cooperi is variable and 3 varieties are distinguished.
There are several other tree-sized Euphorbia spp. with medicinal uses.
Euphorbia magnicapsula S.Carter occurs in East Africa. In Kenya the crushed roots in water are given to sheep and goats to treat coenurosis, an infection with tapeworm larvae. The dried stems with the thorns burnt off are crushed in water and cattle are given the water to drink to treat venereal diseases. Euphorbia magnicapsula is cultivated as an ornamental pot plant in the United States.
Euphorbia nyikae Pax ex Engl. occurs in Kenya and Tanzania. In Kenya the latex is added to Acokanthera arrow poison used by the Giriama people. Young pounded stems are thrown in water as fish poison. In Tanzania a root decoction or latex in soup is drunk to treat urinary tract infections and epilepsy. Euphorbia nyikae is also planted as a hedge.
Euphorbia bussei Pax has the same distribution area and can be confused with Euphorbia nyikae. Stems of Euphorbia bussei are used by the Kamba people to build grain stores.
Euphorbia trigona Mill. from Central Africa, Angola and Malawi is commonly planted as a ritual plant and hedge near villages, especially in Gabon. It is possibly of hybrid origin, as it is only known in cultivation and is not known to flower. The latex is an additive to Periploca nigrescens Afzel. arrow poison, and is also used as fish poison or as a criminal poison. The latex is also used during trials by ordeal. In Congo some drops of latex in palm wine are taken in severe cases of constipation or in case of an epileptic attack. Euphorbia trigona is widely cultivated as a pot plant. The latex contains 8-methoxyingol esters, which are very irritant to the skin. It also contains lectins with potent erythrocyte agglutinating ability.
Euphorbia cooperi occurs in wooded grassland and on rocky hillsides, usually forming colonies, at 200–1500 m altitude. It flowers from September to October. The ripe fruits burst open, flinging seeds several metres away.
Euphorbia cooperi is easily propagated from seeds or cuttings, which must be dried before planting to prevent rotting. Great care must be taken when collecting cuttings, to prevent the poisonous latex from coming into contact with skin or eyes. Euphorbia cooperi does not require much water.
Euphorbia cooperi is relatively common in its area of distribution and there are no signs of genetic erosion. As a succulent Euphorbia species, its trade is controlled under CITES appendix 2.
The latex of Euphorbia cooperi is in general too toxic to be medicinally used. Several irritant and cocarcinogenic derivatives of 16-hydroxy-12-desoxyphorbol were isolated, indicating that its use in modern medicine will be limited.
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- Sosath, S., Ott., H.H. & Hecker, E., 1988. Irritant principles of the spurge family (Euphorbiaceae) XIII. Oligocyclic and macrocyclic diterpene esters from latices of some Euphorbia species utilized as source plants of honey. Journal of Natural Products 51(6): 1062–1074.
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- G.H. Schmelzer, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
Correct citation of this article
Schmelzer, G.H., 2008. Euphorbia cooperi N.E.Br. ex A.Berger. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 28 July 2021.
- See the Prota4U database.