Euphorbia globosa (Haw.) Sims
Common names: globose euphorbia, globose spurge (Eng.); eierpol, knopmelkbol, langbeentjie (Afr.)
The Eastern Cape Province is home to the charming and spineless Euphorbia globosa. This dwarf succulent, from a near distance, appears as an arrangement of green, scaly marbles supported by brown-grey marbles underneath. The top spherical bodies are topped with a stalked crown, from which flowering occurs and to which another marble-like body is added. This results in a fairly spread cluster of balls, and when cultivated, makes a beautiful potted plant.
Euphorbia globosa is a dwarf succulent composed of usually round, scaly, green-grey spherical bodies, growing in circular clusters. This succulent has a spreading growth form when found in its natural habitat (Court 2010), with a hidden underground stem. In cultivation, the plant tends to grow upwards, seemingly like connected beads. The branches emerge at ground level, composed of an elongated structure made up of connected marble-like bodies. As a mechanism to reduce water loss, as in many succulents, the plant lacks proper developed leaves and has few, small leaves.
The inflorescence is borne on a noticeable stalk extending from the spherical body, with a crown-like structure called a cyathium.
The greenish, 10 mm in diameter cyathium, with bright yellowish tips, is made up of several reduced male flowers encircling the female flower. The cyathium houses numerous glands.
Flowering takes place in spring, and gives rise to a smooth, curved, fruit capsule. The fruit bursts open to release seeds.
Euphorbia globosa is a slow-growing and long-lived plant.
According to the Red List of South African plants, checked on 16 January 2017, Euphorbia globosa is assessed as Endangered (EN). It is threatened because of coastal development, which is destroying its habitat. It is a rare species, with a small natural range and is known from less than 5 locations.
Euphorbia globosa is listed on Appendix 2 of CITES, and international trade in this plant requires a permit.
Distribution and habitat
Euphorbia globosa is endemic to the Eastern Cape Province, occurring on low stony hills near the coast, in Albany Thicket and Succulent Karoo, on the outskirts of the Nama Karoo Biome, from Port Elizabeth to Uitenhage. It thrives in rocky and sandy environments, and it usually occurs in isolated patches. The plant is frost tolerant, requiring little rainfall and can withstand high temperatures of about 40ºC.
Derivation of name and historical aspects
Euphorbia is named in honour of Euphorbus, physician to King Juba II of Mauritania (24 BC). The species name globosa, is derived from the rounded and bulby ‘globose’ growth form of the plant.
This genus was named by Carl Linnaeus, and it is placed in the family, Euphorbiaceae commonly known as spurges. The family has over 2 000 species distributed across the world. The genus is divided into four groups; Esula (approximately 500 species), Euphorbia (250 species), Rhizanthium and Chamaesyce respectively having 88 and 18 species occurring in southern Africa. Members of the genus Euphorbia have different growth forms, ranging from herbs, shrubs and huge, well-developed trees. Euphorbia species differ from the cacti (Family: Cactaceae), by the presence of poisonous milky latex and in addition, having small flowers.
The cyathium of the Euphorbia globosa has several glands and thus makes it a good source of food for insects, such as flies of the Diptera order. Seeds are dispersed by the wind as the fruit bursts open.
The plant is used for ornamental purposes as it makes a good potted and garden plant. It is not known to be used in traditional medicine.
The poisonous milky latex in some species of Euphorbia is introduced into a river to stupefy fish or is mixed with wood extracts of Bushman’s poison plant and acacia gum, to make poison for hunting arrows. The latex of Euphorbia ingens is used by the Basotho and Vhavenda as a cancer remedy, whereas the Zulu people take a minute dose as a purgative. In other countries such as Mexico, species of Euphorbia are used to treat gastro-intestinal infections (E. gaumeri, E. schlechtendalii) and obesity (E. golondrina, E. tithymaloides). Snakebite in Sri Lanka is treated with extracts of Euphorbia antiquorum and Euphorbia tortilis.
Growing Euphorbia globosa
Euphorbia globosa is an ornamental plant, and does well in a succulent garden or rockery, situated in a full sun position, with well-drained soil. Grow it with companion plants such as the mesembs (species of Lampranthus and Drosanthemum). It is drought tolerant and suitable for arid gardens. It also does well in containers. Water sparingly in summer and keep dry in winter.
Propagate by seeds or cuttings. Sow seeds in spring or summer. Take a stem cutting and allow the wound to dry to form a callus. Plant the cutting in a well-drained potting mix and place in a cool, light, but shaded spot. Water the cutting and leave it for about 3 months without water. Once rooted, water it again, but make sure the water drains away, and slowly expose the plant to more sunlight, to encourage growth. Fertilize with a 5-10-5 solution of phosphorus (P) to nitrogen (N).
- Alonso-Castro, A.J., et al. 2015. Plants used in the traditional medicine of Mesoamerica (Mexico and Central America) and the Caribbean for the treatment of obesity. Journal of Ethnopharmacology 175: 335–345.
- Cactus art nursery: Euphorbia globosa. http://www.cactus-art.biz/schede/EUPHORBIA/Euphorbia_globosa/Euphorbia_globosa/Euphorbia_globosa.htm. Accessed 2017/01/16.
- Court, D. 2000. A revised Succulent Flora of southern Africa. Balkema, Rotterdam.
- Dharmadasa, et al 2016. Ethnopharmacological survey on medicinal plants used for snakebites treatments in Western and Samarabamuwa provinces in Sri Lanka. Journal of Ethnopharmacology 179: 110–127.
- Gardening know how: fertilizing cactus plants. https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/fertilizing-cactus-plants.htm. Accessed 2017/01/20.
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- iSpot southern Africa. http://www.ispotnature.org/search/node/euphorbia%20globosa Accessed 2017/01/20
- Thiselton-Dyer, W.T. 1925. Thymelaceae-Ceratophylleae. Flora capensis, Vol 5 (2)
- Vera-Ku, M., et al 2010. Medicinal potions used against infectious bowel diseases in Mayan traditional medicine. Journal of Ethnopharmacology 132: 303–308.
Lesiba Papo & Tandiwe Nkonki
National Herbarium, Pretoria
Photos: Andrew Hankey
Plant Type: Succulent
SA Distribution: Eastern Cape
Soil type: Sandy
Flowering season: Spring
Flower colour: Green, Yellow
Aspect: Full Sun
Gardening skill: Easy