A perfect example of convergent evolution, Alluadia is a genus of plants that at first glance look just like our Ocotillo. In fact they are only found in Madagascar and not even remotely related. The six species of Alluadia along with Didieria and other genera of spiny succulents make up what is known as Madagascars "Spiny Forest". In it's native habit Alluadia varies from shrublike plants 6 foot tall to tree like monsters 60 feet tall. Some branch profusely and others are more solitary. All are deciduous in the dry season but leaf out virtually over night when the rains come. Like our Ocotillo they produce flowers in bunches at the stem tips.
Alluadia procera, above, is probably the most common species in cultivation. 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, look out! This is one of the 60 footers! The picture below was taken at the Desert Museum in Tucson of two 12 foot stalks. They're each about 5 inches around at the base. I should have asked how long ago they were planted, I want to try one of these in the ground.