Cyanea koolauensis, a member of the bellflower family (Campanulaceae) and a short-lived perennial, is an unbranched shrub 1 to 1.5 m (3.5 to 5 ft) tall with woody stems and linear to narrowly elliptic leaves with a whitish underside. The leaf edges are hardened with shallow, ascending, rounded teeth. Cyanea koolauensis is distinguished from other species in this endemic Hawaiian genus by the leaf shape and width; the whitish green lower leaf surface; and the lengths of the leaf stalks, calyx lobes, and hypanthium (base of flower) (Lammers 1999).