Euphorbia caput-medusae (Medusa's head)
Fruits of Euphorbia caput-medusae (Photo: Wolfgang Stuppy)
Euphorbia caput-medusae L.
Least Concern (LC) according to the Red List of South African Plants 2009, following IUCN Red List criteria.
Sandy flats and rocky coastal outcrops.
The milky sap (latex) is a skin and eye irritant.
About this species
There are more than 2,000 species of Euphorbia (spurge). They range widely in habit from trees and succulent perennials to small annual herbs. They all produce caustic milky sap.
Euphorbia caput-medusae was introduced from South Africa to the Netherlands around 1700 and described by Linnaeus in his Species Plantarum (1753). Linnaeus had previously worked for George Clifford, a banker and one of the directors of the Dutch East India Company (Verenigde Oostindische Compagnie, VOC). Clifford owned a garden (Hartekamp) near Haarlem, in which he grew a great variety of plants, many sent to him by VOC employees in the Cape. As a result, Linnaeus had an unrivalled opportunity to get to know some of the South African plants coming into Europe at that time, and his work in cataloguing Clifford’s plants, published in 1737 as Hortus Cliffortianus, was to stand him in good stead when he came to organise his later work.
The Latin (and common) name ‘head of Medusa’ describes the plant well, and it is likely that this was among the species grown in Clifford’s garden.
Refer to the World Checklist for full list of synonyms.
Geography and distribution
Endemic to the Cape region of South Africa, from Namaqualand to Mossel Bay.
Euphorbia caput-medusae is a sprawling, succulent shrub, reaching 1 m across. It has a rosette of narrow, snake-like, spineless but knobbly branches, each 10–30 mm in diameter that arise from a short woody stem (caudex) and which rapidly lose their leaves . The remaining narrow, fleshy leaves and a cluster of inflorescences are carried at the end of the branches.
The specialised inflorescences (cyathia) each have a cup-shaped involucre (a whorl of bracts around or beneath the inflorescence) that is 12 mm or more across, with five incurved (bent inwards) lobes and five green shining glands. Each gland is divided into 3–6 white linear or forked processes (outgrowths) which form a fringe around the individual male flowers, each of which has a single stamen, and the single female flower with an elongated pedicel (flower stalk).
Illustration from Curtis's Botanical Magazine
The specimen figured in this featured illustration by Matilda Smith was drawn from the garden of La Mortola, Italy, ‘where it flowered in March 1916 - the only difference from the wild plant being in its considerably thicker branches.’
Curtis's Botanical Magazine (Editor: Martyn Rix) provides an international forum of particular interest to botanists and horticulturists, plant ecologists and those with a special interest in botanical illustration.
Now well over 200 years old, the Magazine is the longest running botanical periodical featuring colour illustrations of plants. Each four-part volume contains 24 plant portraits reproduced from watercolour originals by leading international botanical artists. Detailed but accessible articles combine horticultural and botanical information, history, conservation and economic uses of the plants described.
Published for the Royal Botanic Gardens, Kew by Wiley-Blackwell Publishing.
Kew paintings of Medusa’s head
Matilda Smith, who painted the image in Curtis’s Botanical Magazine, was a relation of Joseph Dalton Hooker, Director of Kew from 1865-1885. Hooker trained her as a botanical artist by getting her to draw from living specimens as well as to copy drawings from Curtis’s Botanical Magazine. In 1898 she became the first official paid artist at Kew.
Euphorbia caput-medusae is cultivated as an ornamental, and is a particular favourite of succulent plant enthusiasts.
This species at Kew
Medusa's head is grown behind the scenes, in the Tropical Nursery at Kew.
Kew’s Economic Botany Collection includes a sample of the acrid milky juice from Euphorbia caput-medusae that was donated to Kew by the artist Thomas Baines in 1854. It is available to researchers from around the world, by appointment.
Goldblatt, P. & Manning, J. (2000). Cape Plants. A Conspectus of the Cape Flora of South Africa. National Botanical Institute, Cape Town & Missouri Botanical Garden, St Louis.
Manning, J. & Goldblatt, P. (1996). West Coast: South African Wildflower Guide 7. Botanical Society of South Africa with the Darling Wildflower Society, Cape Town.
Prain, D. (1916). Euphorbia caput-medusae L. Curtis’s Botanical Magazine t. 8673.
Raimondo, D. et al. (2009). Red List of South African Plants 2009. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
World Checklist of Selected Plant Families (2010). Euphorbia caput-medusae. The Board of Trustees of the Royal Botanic Gardens, Kew. Available online (accessed 1 August 2011).
Kew Science Editor: Martyn Rix
Kew contributors: Gill Challen and Steve Davis
Copyediting: Malin Rivers
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