Koa

The Koa tree is the foundation of the native forest. One of the main native plants of Hawaii. You could easily confused it with a mature eucalyptus tree. Although eucalyptus trees aren't too common in the native forest, usually you'll see eucalyptus trees in an area with a lot of human disturbance. Baby koa trees can be confused for albizia trees as well. I have a hard time telling the difference.

Background Information

The koa tree is revered in Ancient Hawaiian culture. Hawaiians used it for canoes and that says a lot, since Polynesians are considered one of the greatest seafaring cultures along with the Viking and I guess the Europeans. This species of plant is categorized in the pea family. There are two endemic species of koa. The traditional koa and its baby cousin the koai'a. According to the book, the koai'a only exist on certain Hawaiian Islands like Maui and Big Island. Today the koa wood is prized for its furniture.

Koa

Koa trees can grow up to 100 feet tall. The leaves are sickle shaped. They produce these pods which are green and holds about a dozen seeds. The pods turns brown when seeds are mature. Koa seeds sprout quickly, but takes a while to grow within its first year.

Baby koa leaves on Olympus trail

Sickle shaped leaves

Flowering in January

Koai'a

My only observation of Koai'a was in cultivation. The tree listed below was cultivated and is located at Ho'omaluhia Botantical Gardens. I can't really tell the difference between this koai'a and a common koa. But the sign said it is a koai'a. I guess I'll go with it until I get to see some in the wild on Big Island.

Interesting Note from Native Plants Hawaii on Koa

Growth is in virtue of symbiosis with special bacteria called rhizobia that live associated with the roots. The bacteria convert, or fix, nitrogen from the air into usable nitrogen fertilizer for plants. The leaves, flowers and branches also provide nitrogen for understory and plants in the area. Koa inoculated with rhizobia tend to be more vigorous trees.

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