''Metrosideros rugosa'', commonly known as the ''lehua papa'', is a tree of the myrtle family which is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the island of

Oahu Oahu (, , sometimes written Oahu) is the third-largest and most populated island of the Hawaiian Islands and of the U.S. state of Hawaii. The state capital, Honolulu, is on Oahu's southeast coast. The island of Oahu and the uninhabited Northwe ...

in the

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

. It is closely related to the widespread and highly variable ōhia lehua (''

Metrosideros polymorpha ''Metrosideros polymorpha'', the ''ōhia lehua'',; is a species of flowering evergreen tree in the Myrtus, myrtle family, Myrtaceae, that is Endemism, endemic to the six largest Hawaiian Islands, islands of Hawaii, Hawaii. It is a member of the ...

''), found throughout the islands. Lehua papa, however, is restricted to a narrow habitat range at the summits of very wet, windswept ridges and cliffs in the Koolau mountains. It is distinguished from ''M. polymorpha'' by having the upper surface of the leaves with the veins deeply indented, and the leaf margins partly rolled (the latter is also found in some ''M. polymorpha'' varieties). It is also of rather distinctive appearance, with a compact shape suited to its windy habitats. Metrosideros rugosa has red flowers.

References

rugosa The Rugosa or rugose corals are an extinct Class (biology), class of solitary and Colony (biology), colonial corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans (e.g., ''Caninia (genus), Caninia'', ''Lopho ...

Endemic flora of Hawaii Trees of Hawaii Flora without expected TNC conservation status {{Myrtaceae-stub