Euphorbia gorgonis
| Light | Bright light to a little direct sun; keep well lit to stay compact |
|---|---|
| Water | Sparingly in the growing season; keep dry through the cool winter rest |
| Soil | Gritty, very free-draining mineral mix (see Soil and potting mix) |
| Temperature | Warmth in summer; keep above freezing, roughly USDA zones 9b–11 |
| Propagation | Seed (needs male and female plants); occasionally by detaching arms |
| Toxicity | Caustic milky latex — a skin and eye irritant, toxic if eaten (see Pests and diseases and handling notes) |
Euphorbia gorgonis is a compact, clumping euphorbia from South Africa, one of the so-called "medusoid" or medusa's-head succulents. It forms a squat, half-buried central stem from which numerous short, knobbly, tuberculate arms radiate outward in a spiralling head, an appearance that has earned it the common name gorgon's head. Like its medusoid relatives it is grown for its curious, snake-like symmetry rather than for showy flowers.
Description
Euphorbia gorgonis grows as a low, spreading cluster rather than an upright plant. At the centre sits a thick, rounded main stem — partly sunken into the ground in habitat — crowned by a rosette of many radiating branches, or "arms". Each arm is short and cylindrical, densely covered in low, blunt tubercles that give it a rough, warty texture, and tapers to a rounded tip. Older plants slowly build up a broad, congested head of these arms, occasionally offsetting to form a wider colony.
The plant is dioecious, meaning individual plants are either male or female, so seed is only set when both are grown together. The small cyathia (the specialised euphorbia "flowers") are borne toward the tips of the arms and are inconspicuous, their nectar glands a dark purple-brown to crimson, and are valued far less than the sculptural form of the plant itself. As with all euphorbias, cut or broken tissue exudes a white, milky latex that is irritating to skin and eyes.
Distribution and habitat
Euphorbia gorgonis is native to the Eastern Cape of South Africa, where it grows in dry, open scrub on stony, pebbly ground. In the wild the swollen central stem contracts down into the soil during drought, so that little more than the flat head of arms shows at the surface — a habit shared by many medusoid euphorbias and one that helps the plant ride out heat and dry spells.
Like the whole genus, Euphorbia is listed under CITES Appendix II, so international trade in wild-collected plants is regulated; nursery-raised plants are the norm in cultivation and are straightforward to own and trade.
Cultivation
This is an undemanding plant by succulent standards, provided its two dislikes — cold wet roots and deep shade — are avoided. Grow it in a very free-draining, largely mineral mix in a pot only a little larger than the plant, and give it the brightest spot you can. Strong light keeps the arms short, fat and tightly packed; too little light stretches them and spoils the neat medusoid shape.
Water thoroughly during warm active growth, then let the mix dry out completely before watering again. Through the cool season keep the plant nearly or entirely dry and frost-free; a dry winter rest greatly reduces the risk of rot. See Watering and Repotting for general technique. Handle with care and wash off any latex promptly — see the note under common problems.
Propagation
Because the species is dioecious, seed requires a male and a female plant flowering together; where both are available, fresh seed germinates readily on a warm, gritty surface kept lightly humid. See Propagation - seed for a full walkthrough.
Vegetatively, an individual arm can sometimes be detached and rooted as a cutting, but the medusoid arms are less willing to root than typical branching euphorbias, and the parent is easily disfigured, so this is done sparingly. Allow any cutting's cut latex to stop bleeding and the wound to callus before setting it in barely-moist mix; see Propagation - cuttings and Propagation - offsets.
Common problems
- Rot — by far the commonest killer, caused by wet, airless soil or watering during the winter rest; the central stem softens and discolours from the base.
- Etiolation — in low light the arms elongate and thin, losing the tight, radiating form.
- Pests — mealybugs (white fluff between the tubercles and at the roots) and the occasional spider mite are the usual offenders; see Pests and diseases.
- Latex irritation — not a plant problem but a grower one: the milky sap irritates skin and is dangerous in the eyes, so wear gloves when cutting and keep the plant away from children and pets.
See also
- Euphorbia — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation - seed · Propagation - cuttings · Pests and diseases