Cyanea grimesiana is a rare species of flowering plant in the bellflower family known by the common name splitleaf cyanea. It is native to Oahu and Molokai, where it is known from 12 occurrences. It is a federally listed endangered species. Like other Cyanea it is known as haha in Hawaiian. This Hawaiian lobelioid is a shrub which can exceed three meters in height. The stem and herbage are prickly. The tubular flowers are up to 8 centimeters long and may be purple, green, or yellow with reddish stripes. The fruit is an orange berry.