Pipturus albidus, known as Māmaki (sometimes Waimea, for its resemblance to olomea) in Hawaiian, is a species of flowering plant in the nettle family, Urticaceae, that is endemic to Hawaiʻi. It inhabits coastal mesic, mixed mesic, and wet forests at elevations of 60–1,830 m (200–6,000 ft). Māmaki is a small tree that reaches a height of 9 m (30 ft) and a trunk diameter of 0.3 m (0.98 ft).
Native Hawaiians made a treatment for illnesses known as ʻea and pāʻaoʻao from the fruit. They also combined fresh māmaki leaves with hot stones and spring water to produce a tisane that was an effective treatment for general debility. Today, packages of dried māmaki leaves are commercially produced.
The bast fibres were used by Native Hawaiians to make kapa (bark cloth) and kaula (rope).
P. albidus is the preferred host plant for the caterpillars of the Kamehameha butterfly (Vanessa tameamea). Māmaki sometimes host the caterpillars of the Green Hawaiian Blue (Udara blackburni).
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