(Picture = Sifaka sp, climbing on Alluaudia, Leonora Enking)
Introduction
The giant island of Madagascar broke away from Africa about 100 million years ago and since then has mostly gone its own way evolutionarily. There are many plant types found nowhere else in the world. Alluaudia is one of those special plant types; they are especially adapted to the drylands in the south and southwest of the island.
The Details
Alluaudia is a genus of six species found in Madagascar; the species grow in the drier parts of the country, the spiny forests. They various species form large shrubs or trees. Because of their overall shape, because they are adapted to drylands, and because they are deciduous, It is tempting to imagine that Alluaudia species are related to the ocotillo of the American West. However, the two groups are not closely related.
The plants have specialized, short stems (very short) on their major stems from which the leaves arise. These small organs are analogous to, but different from, the areoles of cacti. Alluaudia are dioecious; thus individual plants are either male or female.
The plants are spiny succulents and have water-holding stems. The ascending thin stems are iconic. They rise from 20- to 30-ft tall and are slim and somewhat limber. Sometimes lemurs and other primates can be seen in Alluaudia branches.
Related reading: Madagascar Forests
