(Picture = Sifaka sp, climbing on Alluaudia, Leonora Enking)
Introduction
Alluaudia—often called “Madagascar ocotillo”—are spiny, drought-adapted shrubs and trees from the dry southwest of Madagascar. Tall, jointed stems rise from a sturdy base, then branch into clean, candelabra forms that read as sculptural even when leafless. Small leaves are produced close to the spines during the rainy season, then shed as the long dry returns. The resemblance to Fouquieria is striking, yet it is pure convergence; Alluaudia belongs to the Didiereaceae and follows its own rhythm of heat, light, and seasonal leafing.
The Details
Identification. Stems are segmented and often subtly ridged, with neat ranks of areoles bearing paired, sharp spines. New growth pushes short, oval leaves beside those spines, creating precise, repeating patterns up the stem. With age, plants develop strong, upright lines and fork into symmetrical, many-armed crowns that hold their geometry in wind and sun.
Flowers and form. Inflorescences appear near the stem tips, small and tucked among the upper spines. On mature plants the show is understated, yet elegant; the overall architecture carries the display. Notable species include A. procera (tall, robust, and strongly columnar), A. ascendens (slimmer, often more freely branched), and the lower, bushier A. dumosa. All share the same basic vocabulary—paired spines, short leaves, and a clean, vertical rhythm.
Habitat cues. In nature, Alluaudia grows on hot, stony ground with rapid runoff—limestone flats, gravelly benches, and open slopes swept by dry wind. Within a single valley, plants may concentrate on one terrace while the next stands empty, a reminder that microhabitat—slope, exposure, and soil texture—sets the rules.
Seasonal pattern. The leaves mark the calendar: flushes arrive with moisture, then shrink and drop as drought deepens. Spines protect new growth and shade the stem surface; branch spacing keeps light and air moving through the crown. The result is an architecture that is both efficient and striking—minimal foliage, maximum structure.
Handled with care—if only because the spines are close-set and unforgiving—Alluaudia rewards close looking. From a distance you see a bristling candelabrum; up close you notice the tidy ranks of areoles, the precise leaf-and-spine pairing, and the quiet elegance of a plant built for long, dry seasons.
Related reading: Madagascar Forests
