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
Hakalau Forest National Wildlife Refuge numerous deep gulches. Rainfall decreases to about at elevations above , where majestic koa ("Acacia koa") and red-blossomed ōhia lehua ("Metrosideros polymorpha") trees form a closed-canopy forest. Further upslope, above , rainfall decreases to or less and native forest merges into abandoned pastureland where alien grasses and weeds, introduced as forage for cattle, are the dominant vegetation. Since 1989, over 400,000 koa, ōhia, and other native plants have been planted in this area as part of the refuge's reforestation program. The Pua Akala Cabin, located within the refuge, was nominated to the National Register of Historic Places in August 2008.