Euphorbia alluaudii f. cristata
Euphorbia alluaudii f. cristata, the crested Cat Tails Euphorbia, grows its stems into wavy, fan-shaped crests instead of the straight pencil stems of the species. Every plant forms a different shape. The surface is glossy green and dotted with brown leaf scars. The milky sap is toxic.
Origin and Natural Habitat
The crested form is a cultivated selection and does not occur in the wild. The parent species, Euphorbia alluaudii, is native to south-western Madagascar and reaches towards the central high plateau. It grows in subhumid to dry bushland and spiny forest. On the plateau, it grows on inselbergs and well-drained rock faces.
Plant Characteristics
The crest forms when the growing tip spreads into a flat band instead of a point. The stems are pale to bright green. Brown dots mark where leaves once grew, and large pores give the surface a speckled look. Tiny leaves appear at the tips in summer, then fall quickly. Some clones hold a stable crest, while others cluster over one another. Crested plants often send out normal cylindrical stems too. The plant can grow very large.
The sap pours out in quantity when the plant is cut or damaged. It is toxic and dangerous to the eyes, skin and mouth. Wear gloves and eye protection when you handle the plant, and keep it away from pets and children.
Care Guide
Light
Provide bright light, with full sun for the best colour. Light shade is tolerated. In shade, growth thins and stretches.
Soil
A very gritty, free-draining mix is required. The dense, tightly packed crest dries slowly, so wet soil rots it quickly. Use a mix similar to our LDP Super Drainage Mix.
Water
During the growing season, water thoroughly and let the soil dry out before watering again. Do not leave the plant dry for long periods in summer. In autumn and winter, keep the soil dry. Keep water out of the crest.
Pot size
Use a wide, heavy pot that carries the weight of the crest. This plant does not need frequent repotting. Repot in early spring when it outgrows the pot.
Temperature
Euphorbia alluaudii thrives in heat. Keep it above 10°C in winter. Plants kept completely dry survive down to about 2°C, but frost kills them. Never let the roots get cold.
Humidity
This species prefers low humidity and good airflow.
Fertilizing
Feed with a half-strength liquid fertilizer once a month during the growing season. Do not fertilize in autumn or winter.
Growing Season
Euphorbia alluaudii f. cristata grows from late spring to summer. It rests in autumn and winter.
Propagation
This form can be propagated through stem cuttings or grafting. Seed does not give a crested plant.
Stem cuttings: Take cuttings in late spring or summer, while the plant grows. Wear gloves and eye protection. Cut a crested section 8 to 10 cm long with a clean, sharp knife. Rinse the cut end under warm water until the sap stops. Let the cutting dry and callous for one to two weeks. Dip the end in rooting hormone. Plant it in a gritty mix. Keep it warm and in bright light, with good airflow. Water lightly once roots form.
