Gardenia brighamii, commonly known as nānū, naʻu, or forest gardenia, is a species of flowering plant in the coffee family, Rubiaceae, that is endemic to Hawaii.[1]
Gardenia brighamii is a small tree, reaching a height of 5m (16feet).[1] The glossy, dark green leaves[2] are ovate, 2.2- long and 1.5- wide. The petals of the solitary, white flowers are fused at the base to form a tube 15- in length and have six lobes.
Forest gardenia inhabits tropical dry forests at elevations of 350-. It previously could be found on all main islands, but today populations only exist on Maui, Molokaʻi, Oʻahu, and Lānaʻi, and the Big Island.[1]
The total population of G. brighamii is between 15 and 19 trees. There are only two plants in the wild on Oʻahu and one on the Big Island.[3] Major threats to the survival of this species include loss of dry forest habitat and the establishment of invasive species, such as fountain grass (Pennisetum setaceum).[1]
Native Hawaiians made kua kuku (kapa anvils)[1] and pou (house posts) from the wood of nānū.[3] A yellow kapa dye was derived from the fruit pulp.[4] The white, fragrant flowers are used in lei. Today, it is grown as an ornamental plant on the islands.[3]