Euphorbia heptagona, sometimes referred to as the milk barrel or pincushion euphorbia, is a subtropical succulent species of flowering plant in the genus Euphorbia native to South Africa. The species is also grown as a houseplant.
Description Euphorbia heptagona forms dense clusters of small succulent branches. Each branch typically has four ridges, each with a line of long spines. Young spines are often red or yellow, darkening to black as they mature. Like all Euphorbia species, Euphorbia heptagona exudes toxic white latex when damaged.
Euphorbia heptagona closely resembles many cacti, but this resemblance is due to convergent evolution. Euphorbias are not closely related to cacti.
Tests on the plant have identified the presence of flavonoids, alkaloids, tannins, glycosides, anthraquinones, triterpenoids, and phytosterols.
Taxonomy The species was named Euphorbia heptagona in 1753 by Carl Linnaeus. It is classified in the genus Euphorbia as part of the Euphorbiaceae family. It has twelve heterotypic synonyms several varieties, but no accepted varieties.
Table of Synonyms Name Year Rank Anthacantha desmetiana 1858 species Euphorbia atrispina 1915 species Euphorbia atrispina var. viridis 1941 variety Euphorbia enopla 1860 species Euphorbia enopla var. dentata 1906 variety Euphorbia enopla var. viridis 1941 variety Euphorbia heptagona var. dentata 1915 variety Euphorbia heptagona var. fulvispina 1902 variety Euphorbia heptagona var. ramosa 1941 variety Euphorbia heptagona var. subsessilis 1941 variety Euphorbia heptagona var. viridis 1941 variety Euphorbia morinii 1907 species
Names Euphorbia heptagona is known by the common name milk barrel.
Habitat Native to South Africa, Euphorbia heptagona commonly grows in the Eastern Cape and Karoo regions.
It grows best in well-drained soil and with direct sunlight.
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