'Akoko

Chamaesyce deppeana

Description

Chamaesyce deppeana (=Euphorbia deppeana), a type of 'akoko, is an erect shrub with fuzzy branches that grows up to 4 ft (1.2 m) in height. The hairless leaves, generally oval-shaped and often notched at their tips, are between 0.2-0.8 in (5.1-20 mm) long and 0.2-0.5 in (5.1-12.7 mm) wide. They are arranged in two opposite rows along the stem. The leaf margins are usually toothed. The small, petalless flower clusters (cyathia), 0.06-0.1 in (1.5-2.5 mm) wide, are borne singly in the leaf axils and produce small capsules about 0.1 in (2.5 mm) long. Seeds have not been observed. This species is distinguished from others in the genus by having (1) leaves arranged in two rows on opposite sides of the branches, (2) glabrous (smooth) leaves, (3) notched leaf apexes, (4) toothed leaf margin, and (5) cyathia of a certain width.

Habitat

The most visible and accessible plants within the only known population of C. deppeana are confined to a 200-sq-ft (18.6-sq-m) area, portions of which extend to within 15 ft (4.6 m) of the Pali Lookout parking lot, and along the ridge crest and cliff faces on the windward side. The remaining plants are scattered on an adjacent steep, exposed, windswept slope growing with alien grasses and shrubs.

Associated species include Carex sp., kookoolau, 'ohi'a, and Eragrostis sp. (kawelu). This population is found at an elevation of approximately 1,000 ft (304.8 m).

Distribution

C. deppeana, known historically only from southern Oahu, was thought extinct until recently; the few specimens collected had been taken prior to the twentieth century. In 1986 Joel Lau and Sam Gon of the Nature Conservancy of Hawaii rediscovered the species on state land in the southern Koolau Mountains of Oahu in Nuuanu Pali Wayside State Park near the Pali Lookout. About 50 individuals survived at this location in 1994.

Threats

The major threats to the single known population of C. deppeana are (1) competition for water, space, light, and nutrients with various alien plants such as common ironwood, Hilo grass, and Christmas berry; (2) fire; (3) the possibility of adverse impacts by human activities; and (4) the risk of extinction from naturally occurring mortality due to the limited number of individuals and restricted range.

Conservation and Recovery

C. deppeana is being propagated at the National Tropical Botanical Garden. Specific efforts should be made to immediately weed and protect the remaining extant population. A coordinated fire protection plan for endangered plants on state park lands needs to be developed and implemented.

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/

Pacific Remote Islands Ecological Services Field Office
300 Ala Moana Blvd., Room 3-122
P.O. Box 50088
Honolulu, Hawaii 96850
Telephone: (808) 541-1201
Fax: (808) 541-1216

Reference

U. S. Fish and Wildlife Service. 28 March 1994. "Endangered and Threatened Wildlife and Plants: Endangered Status for 11 Plant Species from the Koolau Mountain Range, Island of Oahu, HI." Federal Register 59:14482-14492.