Gymnostoma is a
genus of about eighteen species of trees and shrubs, constituting one of the four
genera of the plant family
Casuarinaceae. The species grow naturally in the tropics, including at high altitudes having
temperate climates, in forests in the region of the western
Pacific ocean and
Malesia. In
New Caledonia, published botanical science describes eight species found growing naturally, which botanists have
not found anywhere else (endemics). Additional species have been found across
Burma,
Sumatra,
Borneo, the
Philippines,
Sulawesi,
Ambon Island, the
Moluccas,
New Guinea, the
Bismarck Archipelago, the
Solomon Islands, and one endemic species each in
Fiji and the
Wet Tropics of Queensland, Australia.