This is one of the more recognisable members of the genus Euphorbia, usually being a solitary bodied plant which is globular when young but eventually becoming a short columnar plant around 90 to 100mm in diameter and up to 200mm in height. The surface of the plant is grey/green in colour, quite often patterned, usually E.Obesa with a faint chequered pattern, and this patterning can be fairly variable. Flowers are borne on the top of the plant and are either male or female in gender, never both. The botanical term for a plant with this feature is a ‘dioecious plant’, hence you need plants of both sexes to be able to set viable seed. The seed capsule is three chambered and explosive, by which I mean that once the seed has been set and is mature, the capsule splits open in an explosive manner to ensure a wide distribution of the contained seeds. These are black in colour and relatively large, being some 2mm in diameter.
Its root system consists of a main tap root with finer feeder roots emanating from it and the best medium to grow it in is a fairly gritty one. I use a 50/50 mix of John Innes no 3 and small sharp grit, although if you speak to other growers they may tell you differently, everybody has their own thoughts on this, but the bottom line is that it must be free draining. Grow it in full sun with good air circulation to prevent scorch. Some slight shading in the hotter summer months would also not come amiss.
The plant comes from south of Graaff–Reinet in the Eastern Cape district of South Africa. It is fairly rare in habitat due to over–collecting in the past and is now a protected plant. There is another Euphorbia which looks a bit like Euphorbia obesa called Euphorbia symetrica but this is found to the north of Willowmore, a little further to the east. This is also protected. However both plants come relatively easily from seed.
The plant shown is one I obtained some 7 years ago and is a multi–headed clone which currently fills a 150mm diameter pan. Growth of the individual bodies is somewhat slower that a single-bodied plant but cultivation is exactly the same.
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