Aupaka (Isodendrion hosakae)
|January 14, 1991
|A tropical shrub with evergreen leaves.
|Tropical grassland and pasture.
|Habitat damage and browsing by introduced mammalian herbivores.
The aupaka is a branched, upright, evergreen shrub, generally 3-6 ft (1-2 m) tall. The leaves are 2-6 in (4-16 cm) long, somewhat leathery, and broadly elliptic in outline. The flowers are fragrant and borne singly along the stems. The flowers have five petals, which are colored purple with greenish-white edges on the outside, and dusty purple on the inner face of the lobe. The flowers are insect-pollinated, and new plants are established from seedlings. The fruit is a green, elongate capsule.
The critical habitat of the aupaka is on cattle pastures of the Parker Ranch and the adjacent Hawaiian Home Lands. This habitat is typically dry and windy, and the soil is well drained and composed largely of volcanic cinder and ash. The specific microhabitat needs of the aupaka are not yet well studied.
The aupaka is a locally evolved (or endemic) plant that only occurs in the Waikoloa region of the South Kohala District on the island of Hawaii. The Hawaiian archipelago is extremely rich in endemic species; about 89% of the indigenous flowering plants occur nowhere else in the world.
The principal threat to the aupaka is associated with browsing and habitat destruction caused by introduced mammalian herbivores, especially domestic cattle and wild goats. Habitat damage and competition with introduced species of plants are also important, especially that associated with fountain grass (Pennisetum setaceum ). Disturbances caused by wildfire and cinder mining are also risks to the rare aupaka. There are only three populations of aupaka, in total comprising about 350-375 individual plants.
Conservation and Recovery
Management efforts to conserve the aupaka are mostly aimed at preventing grazing and wildfire in its remaining critical habitat. The State Division of Forestry and Wildlife has erected protective fences around some of the surviving populations of the aupaka to protect the rare plants from grazing mammals. Biologists working with this agency and the Lyon Arboretum of the University of Hawaii at Manoa have grown plants from cuttings taken at Parker Ranch. These may eventually yield surplus plants for out planting into the wild, to increase the depleted populations of aupaka there. No seeds of the aupaka exist in any seed banks. The critical habitat of the aupaka should be strictly protected by acquiring the land and establishing ecological reserves, or by negotiating conservation easements with the private landowners.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
U. S. Fish and Wildlife Service
Ecological Services Field Office
300 Ala Moana Boulevard, Room 3108
P.O. Box 5088
Honolulu, Hawaii 96850
Telephone: (808) 541-3441
Fax: (808) 541-3470
U. S. Fish and Wildlife Service. 2000. "The Recovery Plan for Lipochaeta venosa & Isodendrion hosakae." http://www.r1.fws.gov/pacific/wesa/lipoven_isodhasidx.html