Euphorbia alluaudii (Cat Tails Euphorbia)

Euphorbia alluaudii is a semisucculent, strongly branched shrub or small tree in the Euphorbiaceae family, native to Madagascar, where it occurs in dry shrubland and rocky habitats. It develops numerous fleshy, cylindrical green stems bearing small, short-lived leaves and often appears almost leafless. Plants are dioecious, with male and female flowers on separate individuals, and produce small greenish-yellow cyathia. Its pencil-like stems resemble those of Euphorbia tirucalli, but the two are distinct species. Two subspecies are recognized: subsp. alluaudii and subsp. oncoclada, the latter formerly known as Euphorbia oncoclada. Tirucalia alluaudii is a taxonomic synonym, while Euphorbia leucodendron is now placed under subsp. alluaudii.

Euphorbia alluaudii grows best in full sun to bright light and porous, very well-drained soil. It is adapted to seasonal drought and should be watered sparingly, allowing the soil to dry between waterings; prolonged wet conditions can cause rot. Its unusual architecture makes it suitable for succulent collections, dry tropical gardens, and containers. Frost sensitive, it is best suited outdoors to USDA Zones 10-11 and requires protection from cold elsewhere. The milky latex is irritating to skin and eyes and toxic if ingested.