Rhododendrons occur in Borneo and Sumatra, descending to the level of the sea.
Wild ginger, elder and sumach are common, and in the mountain areas, rhododendrons, mountain laurel and azaleas.
On the dome-like tops of such mountains as are too high for trees are large clusters of rhododendrons and patches of grasses fringed with flowers.
The alpine flora, beginning at 6000 ft., is specially characterized by its rhododendrons, pines (Araucaria and Libocedrus), and palms, by numerous superb species of Agapetes (Ericaceae), and on the summits by an extraordinary association of species characteristically European (Rubus, Ranunculus, Leontodon, Aspidium), Himalayan, New Zealandian (Veronica), Antarctic and South American (Drymus, Libocedrus).
Higher up, in the picturesque gorges, grow rhododendrons, willows, Potentilla fruticosa, Spriaeae, Lonicereae, &c., and the rains must evidently be more copious and better distributed.