About Metrosideros rugosa A.Gray
Metrosideros rugosa, commonly called lehua papa, is a tree in the myrtle family that is endemic to the island of Oʻahu in the Hawaiian Islands. It is closely related to Metrosideros polymorpha, the widespread, highly variable ʻōhiʻa lehua that grows across all the Hawaiian Islands. Unlike its widespread relative, lehua papa is restricted to a narrow habitat range: it only grows at the summits of very wet, windswept ridges and cliffs located in the Koʻolau mountains. This species can be distinguished from M. polymorpha by its leaf traits: the upper leaf surface has deeply indented veins, and its leaf margins are partly rolled. Partly rolled leaf margins are also seen in some varieties of M. polymorpha. Lehua papa has a distinctive compact growth shape, which is adapted to its windy habitat. Its flowers are red.