Euphorbia leuconeura
| Light | Bright, indirect light; tolerates some direct sun with acclimatisation |
|---|---|
| Water | When the top of the soil dries; reduce in winter |
| Soil | Free-draining but slightly richer than a pure cactus mix (see Soil and potting mix) |
| Temperature | Warmth-loving; keep above about 10 °C, no frost (USDA zones 10–11) |
| Propagation | Self-sown seed (readily); also cuttings |
| Toxicity | Toxic — milky latex irritates skin and eyes; keep away from pets and children |
Euphorbia leuconeura, commonly known as the Madagascar jewel, is an easy, upright succulent grown for its dark green leaves boldly marked with pale white veins, carried in a rosette at the top of a slender, ridged stem. Native to Madagascar, it is one of the most forgiving members of the huge genus Euphorbia and is famous among growers for cheerfully sowing itself around the greenhouse or windowsill.
Description
Euphorbia leuconeura grows as a single erect stem, columnar and distinctly ribbed, that can reach a metre or more in age though it is usually kept much smaller as a houseplant. The stem is lined with paired, persistent spine-like stipules along its angles, and old leaf scars give it a textured, almost braided look lower down.
The leaves cluster toward the crown in a loose rosette. They are obovate to spoon-shaped, deep green, and traced with a network of whitish veins that give the plant both its "Madagascar jewel" name and much of its charm; the undersides are often flushed reddish. Small, inconspicuous flowers (technically cyathia, as in all euphorbias) appear in the leaf axils near the top. They are not showy, but they are followed by seed capsules that ripen and burst explosively, flinging seed a surprising distance — the source of the plant's self-seeding habit.
Like all euphorbias, the plant contains a milky white latex that flows freely when any part is cut or broken. It is an irritant and should be treated with care.
Distribution and habitat
The species is endemic to Madagascar, where it grows in seasonally dry, warm conditions. In cultivation it has spread worldwide as a houseplant and is thoroughly naturalised in collections through its self-sowing.
Cultivation
Euphorbia leuconeura is among the easiest succulents to keep, which is a large part of its popularity. Give it bright light — a sunny or lightly shaded window is ideal — and it will develop the best leaf colour; too little light makes the plant stretch and pale. It appreciates a potting mix that drains freely but holds a little more moisture than a strict cactus blend, since it is less drought-adapted than many desert euphorbias.
Water when the top of the soil has dried, more generously in warm weather and sparingly in winter, when growth slows. Keep it warm and out of frost; sustained cold or wet, cold roots are the main causes of trouble. Feed lightly during the growing season. See Watering and Repotting for general technique.
When handling, pruning or repotting the plant, protect your skin and especially your eyes from the latex, and wash off any sap promptly.
Propagation
The plant is best known for propagating itself: the ripe capsules eject seed that germinates freely in neighbouring pots, so most growers acquire "spare" seedlings without any effort. To propagate deliberately, collect the seed before the capsules burst and sow it warm on a free-draining surface (see Propagation — seed).
Stem cuttings are also possible. Allow the cut end to stop bleeding and callus for a few days before potting, and rinse or blot the latex from the cut first (see Propagation — cuttings).
Common problems
- Rot — from overwatering or cold, wet conditions; the stem softens, usually from the base.
- Etiolation — too little light causes weak, stretched growth and faded veining.
- Leaf drop — some lower-leaf loss is natural as the stem ages, but sudden drop often follows cold draughts or a dry spell.
- Pests — mealybugs and, in dry indoor air, spider mites; see Pests and diseases.
- Unwanted seedlings — not really a problem, but the vigorous self-seeding can surprise you; pull or pot up volunteers as you like.
See also
- Euphorbia — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation — seed · Propagation — cuttings · Pests and diseases