Euphorbia cylindrifolia
| Light | Bright, filtered light to a few hours of gentle direct sun |
|---|---|
| Water | Sparingly in growth; keep dry during its winter rest |
| Soil | Very gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Warm and frost-free; keep well above freezing (roughly USDA zones 10–11, almost always grown under cover) |
| Propagation | Division of rhizomes and stem cuttings; seed where available |
| Toxicity | Toxic — the milky sap is a skin and eye irritant; keep away from pets and children |
Euphorbia cylindrifolia is a small, mat-forming succulent from southern Madagascar that spreads underground by slender rhizomes to form a low, creeping colony. From these it sends up clusters of narrow, cylindrical or slightly grooved gray-green leaves, giving the plant a curious, almost coral-like or medusoid appearance that has made it a favourite among collectors of dwarf Madagascan Euphorbia.
Description
Euphorbia cylindrifolia is a dwarf, geophytic species that grows from a tuberous rootstock and creeping, pencil-thin rhizomes. Rather than forming a single upright stem, it spreads laterally just below or at the soil surface, throwing up short branches tipped with rosettes of leaves. The leaves are its most distinctive feature: narrow and cylindrical to trough-shaped, gray-green and often flushed with subtle bronze or reddish tones underneath, curling and twisting in a way that gives established clumps a tangled, textured look.
Like all members of the genus, it carries the specialised flower structures called cyathia rather than true flowers. These are tiny and modestly coloured, appearing on short stalks among the leaves. Every part of the plant contains the milky white latex typical of Euphorbia, which flows freely when the plant is cut or damaged.
Distribution and habitat
The species is endemic to a restricted area of southern Madagascar, where it grows in dry, seasonally arid scrub. In habitat much of the plant sits at or below ground level, with the rhizomes and tuber sheltered in gritty, well-drained soil and only the leafy shoots exposed. This growth habit helps it survive prolonged drought and the intense heat of its native range.
As with many narrowly distributed Madagascan succulents, wild populations are limited and vulnerable to habitat loss and over-collection. In common with other succulent members of the genus, E. cylindrifolia is listed under CITES Appendix II, which regulates international trade; nursery-propagated plants are widely available and are the responsible choice for growers.
Cultivation
Euphorbia cylindrifolia is a rewarding dwarf succulent but, like most Madagascan euphorbias, it dislikes cold, wet conditions. Grow it in a very free-draining, largely mineral mix in a pot or shallow pan that gives the rhizomes room to run. Give it bright, filtered light with perhaps a few hours of gentle direct sun; too little light draws the shoots out and dulls the compact character that makes the plant appealing.
Water moderately while it is in active growth in the warmer months, always letting the mix dry out before watering again, and keep it warm. Through the cooler months the plant takes a dry rest — reduce or withhold water and never let it sit cold and damp, which quickly leads to rot of the tuber and rhizomes. It resents cold, so keep it comfortably above freezing at all times. See Watering and Repotting for general technique.
Take care whenever handling or pruning the plant: the milky sap is an irritant to skin and especially the eyes. Wash off any sap promptly and keep the plant out of reach of pets and children.
Propagation
Because the plant spreads by rhizomes, an established clump can be lifted and separated into rooted pieces — the most reliable method. Stem cuttings also root well — allow the cut surfaces to callus for a few days, and rinse or blot away the latex first, as it can hinder rooting. The species is dioecious, so seed is set only where separate male and female plants are grown together, and raising plants from seed is an uncommon route for hobbyists. See Propagation — cuttings and Propagation — offsets for detailed technique.
Related species
E. cylindrifolia is grown as the wild species, prized for its natural medusoid form. It is sometimes offered alongside, and confused with, related dwarf Madagascan euphorbias such as Euphorbia decaryi, with which it shares a creeping, rhizomatous habit.
Common problems
- Rot — the most frequent cause of loss, almost always from overwatering, a poorly draining mix, or cold wet conditions reaching the tuber and rhizomes.
- Etiolation — too little light stretches the shoots and loosens the compact clump.
- Pests — mealybugs (white fluff at the leaf bases and on the roots) and spider mites are the usual offenders; inspect the crowded shoots regularly.
See also
- Euphorbia — the genus overview
- Euphorbia decaryi — a closely related dwarf Madagascan species
- Soil and potting mix · Watering · Propagation — cuttings · Propagation — offsets · Repotting · Pests and diseases