Koki'o (Kokia drynarioides)

views updated

Koki'o

Kokia drynarioides

StatusEndangered
ListedDecember 4, 1984
FamilyMalvaceae (Mallow)
DescriptionA tropical tree.
HabitatDry tropical forest.
ThreatsHabitat loss and deleterious effects of non-native plants and herbivorous mammals.
RangeHawaii

Description

The koki'o, also known as hau-hele'ula, and as Hawaii tree cotton, is a small tree. It grows as tall as 15 ft (4.5 m), with a thick trunk and grayish-brown bark. The leaf petioles are 2.0-3.5 in (5-9 cm) long, and the blades are thin, leathery, glabrous except where the veins join at the base, 3.5-5.1 in (9-13 cm) in diameter, and star-shaped with 5 to 7 triangular lobes one-third as long as the blade. The flowers occur singly in axils of the upper leaves. The flower stalk is up to 6 in (15 cm) long, and has a 0.6-inch (15-mm) bract at the middle. The flower bracts are 1.0 to 1.4 in (2.5-3.5 cm) long, egg-to heart-shaped, leathery, and ascending. The calyx is 0.4 in (1 cm) long, becoming larger in fruit. The petals are quite large (3.1 in by 2.4 in; 8 cm by 6 cm), orangered in color, obovate in shape, reflexed, and finely silky hairy on the outside. The staminal column (fused stamens) is 2.6 in (6.5 cm) long and dark-red in color. The ripe seedpod is 1.3 in (3 cm) in diameter, globose, thick, and woody. The seeds are about 0.7 in (18 mm) long, egg-shaped, and covered with reddish brown wool.

Habitat

The koki'o occurs in native dry tropical forest.

Distribution

The koki'o is a locally evolved (or endemic) species of the island of Hawaii. The Hawaiian archipelago has an extremely large fraction of endemic species; about 89% of the indigenous flowering plants occur nowhere else in the world.

Threats

Indigenous Hawaiians used the bark of the koki'o to make a red dye used to color fishnets, and as a medicinal plant. After the European colonization, the extensive development of pastures for cattle grazing resulted in the extensive cutting of koki'o trees and habitat destruction. In total, about 90% of the dry forest of Hawaii has been lost, and at least 10% of the indigenous species of the ecosystem are extinct. The koki'o is also severely threatened by invasive non-native plants that change its habitat and provide intense competition, by browsing by introduced mammalian herbivores (such as pigs, cattle, and goats), and by ongoing human disturbances and land development. In the mid-1990s, the koki'o was known in the wild from only three small populations with a total of fewer than 10 individuals.

Conservation and Recovery

Survival of the koki'o in the wild requires the strict protection of its remaining wild habitat, and active management to reduce the intensity of stress caused by introduced plants and mammals. The locations of its surviving populations have been designated as "critical habitat," and are being protected from disturbance by road-building and other human activities. The koki'o is also being grown in cultivation. Eventually, captive-reared plants should be transplanted to suitable wild habitats to enhance the abundance of the rare koki'o there.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
(503) 231-6121
http://pacific.fws.gov/

U. S. Fish and Wildlife Service
300 Ala Moana Boulevard, Room 3108
P.O. Box 5088
Honolulu, Hawaii 96850
Telephone: (808) 541-3441
Fax: (808) 541-3470

Reference

Conservation Management Institute. 13 March 1996."Cooke's Koki'o." Endangered Species Information System, Virginia Tech, Blacksburg. (http://fwie.fw.vt.edu/WWW/esis/lists/e701007.htm) Date Accessed: July 6, 2000.