Alluaudia procera

Also known as Madagascar ocotillo, this is an interesting succulent and one that is not seen in every collection. This plant matures into a vertical tower of stems reaching over 18 m high (in habitat).

Description: Spiny and scarcely branched or occasionally columnar, small succulent tree with a very upright habit that looks a lot like a "crown of thorns".
Flowers: Yellowish white in crowded clusters at the end of the branches. Flowers will be produced in mature specimens taller than 3 m on separate male and female plants.
In winter the plant loose all its leaves.

Cultivation:Alluaudia procera Needs full sun or high interior lighting with a very well drained soil mix and freely circulating air. Plants are watered and allowed to dry thoroughly before watering again. tolerate temperatures as low as 0° C (Avoid any frost!). If grown in the home environment, the ideal temperatures should run between 20° to 30° C with winter time temperatures around 10°C. During the winter months, the plant will drop all of its leaves and water should be reduced to the minimum during this period. Not freely branching. Once this plant is established in its new pot, it should be cut back to 7-10 cm in height to encourage branching. The cutting removed can be rooted easily, and the process repeated. If pruned and kept somewhat pot bound, they can be maintained at a manageable size, depending on what "manageable size" means to you. If planted in the landscape however, It will often drop all its leaves when it decides to take a rest. When this happens, cut down on the watering until the leaves start to appear again.

Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz

Blooming Season	Late spring-mid summer
Common Name	Madagascar ocotillo
Dormancy	Winter
Family	Didiereaceae
Flower	Gold (yellow-orange)
Frost Tolerance	0 °c
Growth Rate	Slow growth
Hardiness Zone	9b to 11
Height	Up to 60 feet
Origin	Madagascar
Scientific Name	Alluaudia procera ocotillo
Shape	Columnar
Sun Exposure	Full sun