Hibiscus arnottianus A. Gray – kokio kekeo ("kokio that is white like the shine of silver") is an
endemic species of hibiscus with white flowers. Three subspecies are
recognized: H. arnottianus arnottianus found in the Waianae Range of
western Oahu; H. a. immaculatus which is very rare (listed as
endangered) on Molokai; and H. a. punaluuensis from the Koolau Range
on Oahu. Perhaps only a dozen plants of H. a. immaculatus exist in
nature in mesic and wet forests. This species is closely related to H.
waimeae, and the two are among the very few members of the genus with
fragrant flowers. Sometimes planted as an ornamental or crossed with H.
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)
USDA Zone 10a: to -1.1 °C (30 °F)
USDA Zone 10b: to 1.7 °C (35 °F)