Acacia heterophylla Acacia heterophylla Acacia heterophylla, the highland tamarind, is a tree (or shrub in its higher places) endemic to Réunion island where it is commonly named tamarin des hauts The tree has a juvenile stage where its leaves have a pinnate arrangement, but in the adult stage the leaves diminish and the phyllode becomes the dominant photosynthetic structure. It has been introduced into Madagascar where it grows in a subhumid climate at an altitude of about 500–1000 m above sea level. Genetic sequence analysis has shown its closest relative is "Acacia koa" of Hawaii; the estimated time of divergence is about
Acacia koa there are few koa remaining which are both large and straight enough to do so today. In areas where cattle are present, koa regeneration is almost completely suppressed. However, if the cattle are removed, koa are among the few native Hawaiian plants able to germinate in grassland, and can be instrumental in restoring native forest. It is often possible to begin reforestation in a pasture by disk harrowing the soil, as this scarifies seeds in the soil and encourages large numbers of koa to germinate. Experiments at the Hakalau Forest National Wildlife Refuge have shown that ōhia lehua ("Metrosideros polymorpha")