pseudorugosa Metrosideros polymorpha, the ʻōhiʻa lehua,[4] is a species of flowering evergreen tree in the myrtle family, Myrtaceae, that is endemic to the six largest islands of Hawaiʻi.

[5] It is a highly variable tree, being 20–25 m (66–82 ft) tall in favorable situations, and a much smaller prostrate shrub when growing in boggy soils or directly on basalt.

Flowers are usually bright to medium red but orange-red, salmon, pink, yellow, or orange forms are also found.

Metrosideros polymorpha was originally classified as a variety of M. collina, native to Rarotonga, Tahiti, and other islands of Polynesia, but now is generally accepted as a distinct Hawaiian endemic species.

The specific epithet polymorpha, meaning 'many forms', is very appropriate, since individuals of this species exhibit many different morphologies and inhabit a broad range of ecological situations.

[citation needed] Metrosideros polymorpha is the most common native tree in the Hawaiian Islands, tolerating a wide range of soil conditions, temperature, and rainfall.

It grows from sea level right up to the tree line at elevations of 2,500 m (8,200 ft) and is commonly found in moist and dry forests, high shrublands, and is a colonizer of recent lava flows.

Preferred soils are acidic to neutral (pH 3.6–7.4) and either a Histosol, Mollisol, Podsol, Oxisol, Ultisol, or Alfisol.

In the wet forests these include the strawberry guava (Psidium cattleyanum), albizia (Falcataria falcata), and "purple plague" (Miconia calvescens).

Alien grasses such as meadow ricegrass (Microlaena stipoides) may form an understory that prevents or inhibits natural regeneration of the forests.

In drier areas, M. polymorpha has to compete with silk oak (Grevillea robusta) and fountain grass (Cenchrus setaceus).

[11] While ʻōhiʻa itself remains extremely abundant, some species that depend on it such as the ʻakekeʻe (Loxops caeruleirostris) and longhorn beetles in the genus Plagithmysus have become endangered due to forest areas shrinking.

In April 2018, the cause of rapid ʻōhiʻa death was identified as two species of Ceratocystis previously unknown to science: C. huliohia and C. lukuohia.

[14] In native Hawaiian society, it is used in house and heiau construction, as well as to make papa kuʻi ʻai (poi boards), weapons, tool handles, hohoa (round kapa beaters), and kiʻi (statues and idols).

[19] It is said that when a lehua flower is plucked from an ʻōhiʻa tree, the sky will fill with rain representing the separated lovers' tears.