Koa (Acacia koa)

Some of the seed pods that form from koa trees.

This is a forest tree most popularly used for it's hard and study wood. After very varnished pieces made with Koa wood can be extremely expensive. Their are stores on the islands dedicated to selling furniture and good made exclusively from koa wood. Currently a trend is phone cases and watches made from koa wood. 

Picture taken from: http://www.tradewindsfruit.com