Cyanea acuminata (Gaudich.) Hillebr.

Genus: Cyanea

Range: O'ahu; Ko'olau Range. Wai'anae is listed in USFAW, 2008, apparently on army land.

Status: Federally listed Threatened and Endangered; IUCN Critically Endangered C1(3.1). Population is recovering, estimates made in 2007 are for 215-245 mature individuals in 18 populations (USFAW 2008).

Growth form: Treelet, unbranched, 0.3 to 2 m tall.

Image from JSTOR Global Plants

Known as Honolulu Cyanea. This species is now endangered, but in 1919, Rock said this species was "quite common in the mountains back of Honolulu".

Cyanea acuminata was one of the nine plants named by Gaudichaud in his plant descriptions from the 1817-1820 voyage of the Uranie. At that time, Gaudichaud had circumscribed Cyanea based solely on Cy. grimesiana. Thus the genus was described as having spiny branches, long, leaf-like calyx lobes, all anthers bearded, pinnate leaves and blue flowers. Whereas Delissea, to him, was a genus without spines, tooth-like calyx lobes, only two of the anthers bearded, entire leaves and white (red) flowers. Based on these characteristics, our Cyanea acuminata was published as Delissea acuminata. Later calyx lobes, leaf margins and flower color were all shown to be unreliable traits for relationships. Whereas, spines and anther beards only apply to a subset of Cyanea. Hillebrand transferred this species to Cyanea when he recircumscribed the genera.

It has been observed flowering in February and November (USFAW 2003)

Cyanea acuminata's relationship is not certain. Rock (1919) placed it in section Pilosae apparently based on habit. I follow Givnish, 1995 and place it close to the grimesiana clade.

How to identify: One of many lobeliad treelets occuring in the Ko'olau range, Rock says the species can be identified by the numerous, long racemes (18cm) of white flowers arranged along the upper portion of the stem. The white flowers are about 3 cm long, the lobes curved downward, the anthers purple.

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