Koa haole

Leucaena leucocephala

A Hawaiian Invasive Plant

Leucaena leucocephala is native to tropical America where it grows in dry forests. In Hawaii the plant is known as koa haole and is a great example of an alien pest species in Hawaii. The name likely came from its resemblance to the other native tree in the bean family, koa, and haole, alluding to its introduction by white foreigners.


Koa haole is a sturdy shrub or small tree that can reach almost 30 feet tall. The flowering heads (infloresences) resemble white globules that are about one inch in diameter. In reality, these tiny globules are actually composed of many small flowers with white petals. The leaves are pinnately compound with many leaflets. The plant produces several thin pods that surround small brown seeds.

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Written by Rob Nelson

Rob is an ecologist from the University of Hawaii. He is the co-creator and director of Untamed Science. His goal is to create videos and content that are entertaining, accurate, and educational. When he's not making science content, he races whitewater kayaks and works on Stone Age Man.

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