Species Name Acacia koaia
Synonyms Acacia koaia |
Common Name koai'a | koai'e | koa'oha |
CPC Number 17
Natures Serve Global Rank G2
Global Rank Review Date 8/24/2000
Description Species that belong to the genus Acacia are member of the family Fabaceae, which is also commonly referred to as the legume, or pea, family. There are two Acacia species endemic to Hawaii. The first, referred to as Acacia koa sensu stricto, is a fairly common Hawaiian tree that is well known for its decorative wood.
The other, A. koaia, is a rare tree that is adapted to drier conditions and has harder wood, a smaller stature, and more gnarled appearance than its more common relative. A. koaia can be locally abundant in drier habitats, but this habitat is seriously threatened (K. Wood pers. comm. 2002). This rare tree has sickle-shaped leaves that are actually phyllodes, or flat, expanded petioles that take the place leaf blades & perform the same functions. The flowers are formed in heads with cream-colored corollas, long, curled stamens (more than twice the length of the corolla) and pubescent ovaries. (Wagner et al. 1999)
To distinguish between the common and rare species, a number of characteristics can potentially be used. A. koaia pods are laterally flattened with longitudinally arranged seeds, narrower pods and straighter phyllodes than A. koa sensu stricto which has wider pods, laterally arranged seeds, and more curved phyllodes. A confounding problem has arisen because, on the northern coast of Kauai, a population of Acacia spp. has been found with the habit and phyllodes of A. koa sensu stricto but with the pods of A. koaia (Wagner et al. 1999).