Sarcostemma viminale

caustic creeper


Sarcostemma viminale

(L.) R.Br. 1810

pronounced: sar-koh-STEM-uh vim-in-AH-lee

(Apocynaceae — the oleander family)

synonym — Euphorbia viminalis

L. 1753

pronounced: yoo-FOR-bee-uh vim-in-AH-liss

common names: caustic creeper, melktou, Rapunzel plant

native 4Sarcostemma is from the Greek σαρξ (σαρκος) (sarx, sarkos), flesh, and στεμμα (stemma), a wreath or garland, referring to the fleshy inner corona. Viminale is from the Latin viminalis, of or belonging to osiers, referring to the long stems that look as if they could be plaited into baskets.

The taxonomic status of this plant is controversial. Many authoriities now name it Cynanchum viminale (L.) L., but this has not been accepted by all taxonomists

The ‘caustic’ in the common name refers to the burning power of the released latex, and ‘melktou’ is the Afrikaans name for the plant. Rapunzel is not really the name of this plant at all, but a common name of Campanula medium, usually referred to as Canterbury Bells. Our plant’s connection with Rapunzel comes from the fairy tale of that name by the Brothers Grimm. Rapunzel, the heroine of the story, was thus named as a baby when her mother saw some Campanula medium in bloom. The beautiful maiden Rapunzel was shut away in a tower by a wicked witch. The tower was in the middle of the woods, with neither stairs nor door. The only access was by means of Rapunzel’s long hair, which she had to let down from the window, on demand. The hair served as a rope up which first the wicked witch, and, in due course, the handsome prince, could gain access to Rapunzel’s room at the top of the tower. Sarcostemma viminale is called the Rapunzel Plant because it often dangles down like the braids of her hair.

This is a vigorous succulent creeper that grows in trees and shrubs up to several metres, sometimes stifling them. If it has nothing to climb on, it becomes a shrub itself.

It is a leafless plant consisting of smooth cylindrical green stems, pencil-shaped, usually 5 – 10 mm in diameter. The lower base stems have a corky bark. As mentioned above, all parts of the plant exude a milky latex when damaged. Contact with the latex should be avoided.

The star-shaped flowers arise in clusters from the nodes, and have five yellowish sepals curving upwards around less conspicuous white flower parts.

The fruits are follicles like a pair of horns, brown when ripe, opening to release soft hairy seeds.

This is a plant of grassland and bushveld in South Africa, Botswana, Namibia and all inland parts of southern Africa as far north as Kenya – the hotter and drier parts of the country. In coastal regions of Australia, China, India, the Philippines, Thailand and New Caledonia, the plant found is usually a member of the subspecies brunonianum†. This was indeeed the case with the specimens collected by Banks and Solander at Cape Grafton and the Endeavour River in 1770.

The subspecies has only minor differences from the main species, and the flowers are sweet-scented. The subspecies is the plant photographed, growing in the surrounds of the Horseshoe Bay wetlands and on the edge of Nobby Head, Picnic Bay.

dangerous 2The plant is usually avoided by stock, but they will eat it in times of drought when palatable fodder is scarce. The plant is sometimes – but not always – toxic, and may affect horses, cattle, sheep and goats. It attacks the central nervous system and, later, the kidneys. Clinical signs occur within about 8 hours, and death usually occurs 12 – 24 hours later, although the larger animals may take longer to die.


for Robert Brown (1773–1858), Scottish botanist


Photographs taken in Horseshoe Bay 2010-2014
Page last updated 30th march 2019