The Hawaiian cotton tree (Kokia drynarioides), also known as hau hele 'ula or koki'o in Hawaiian, grows as a rare, endangered plant in the wild. The plant's large, bright red flowers make it highly desirable in gardens and landscapes where it grows as an ornamental plant, helping to counteract its disappearance in the island's forests.
Native Hawaiians used the tree for medicinal and household goods for hundreds of years. By the early 1900s, botanists collected a few pounds of seed from the tree due to their concern about the tree's survival. The botanists distributed the seeds to gardens and arboretums. While some Hawaiian cotton trees grow in yards and landscapes in Hawaii, the plant still declined in the wild. According to the United States Botanic Garden, as of 2010 only 10 of the plants grew in the wild today, making it a rare, endangered species.
The Hawaiian cotton tree grows only on the leeward side of the central Pacific Ocean island of Hawaii. The spectacular flowering plant grows in the wild in dry, forested areas that occur on rough lava. The plant prefers extremely well-drained soil at elevations of 1,490 to 6,280 feet. Of the 10 known plants found in the wild, several grow in the lava fields at Pu'u Wa'awa'a and at Kaupulehu in the North Kona district.
A member of the hibiscus family, the cotton tree grows up to 17 feet tall, featuring star-shaped pale green leaves. The plant produces large scarlet flowers resembling twisted hibiscus flowers. The flowers primarily bloom in the spring and summer, but can bloom at any time of the year. Seedpods containing fuzzy golden to reddish-brown seeds mature in the summer or fall. The seeds resemble native Hawaiian cotton, giving the tree its common name.
Invasive weeds such as fountain grass, destruction of the plant's native habitat, and overgrazing by livestock all contributed to making the cotton tree an endangered species. Fire also played a role in decreasing the number of trees growing in the wild. Attempts to manage the habitat where the trees grow continues by federal and state agencies. State and private conservation groups also grow the trees in enclosures in hopes of reestablishing the species.
Nectar-drinking birds, called honeycreepers, rely on the pollen and nectar-filled flowers of the Hawaiian cotton tree as a food source high in protein. With the disappearance of the cotton trees and other native plants associated with the tree, the honeycreeper is now also listed on the endangered species list.
The sap from the tree was used by native Hawaiians to create red dyes for fishnets. Bark from the tree was also made into a medicine to prevent thrush. Due to the tree's rarity, these traditional practices no longer occur.