This subspecies of kokiʻo keʻokeʻo is extremely rare in its native habitat on Molokaʻi where the few remaining plants grow in wet to mesic forests (50-1600 ft.).The generic name Hibiscus is derived from hibiscos, the Greek name for mallow. The specific and subspecific epithets are named in behalf of George Walker Arnott (1799-1868), Scottish botanist, traveler, collector and director of the Glasgow Botanic Gardens. Flowers have a white staminal (stamen) column and fittingly has the botanical subspecies name immaculatus is Latin for “without spots” or “pure.”

Aloalo is the name given for hibiscus in general. Hau is an introduced hibiscus (Hibiscus tiliaceus), perhaps by early Hawaiians. Hau hele literally means “traveling hau.” Kokiʻo kea and Kokiʻo keʻokeʻo literally mean “white kokiʻo” and “white, white [clear white] kokiʻo,” respectively. Pāmakani is a name given to this species of hibiscus and also to a native violet (Viola chamissoniana).
The two native Hawaiian white hibiscuses, Hibiscus arnottianus and H. waimeae, are the only species of hibiscuses in the world known to have fragrant flowers! Two cultivars are recognized for this subspecies: cv. ‘Molokai White’ and cv. ‘Nuuanu White’.