Honohono

Haplostachys haplostachya var. angustifolia

Description

Honohono, Haplostachys haplostachya var. angustifolia, is an annual mint, with thick, square, reddish stems, typically 16 in (40 cm) or more in height. Paired, oblong, moderately angular leaves are finely toothed and highly aromatic. Numerous, large white flowers occur in the leaf axils and become smaller and more densely clustered toward the stem tips. Flowers, which have been observed to bloom in May and June, have the appearance of two lips— the upper smaller and curled back, the lower larger and drooping.

Habitat

This plant is found in an area of scrub vegetation, called a "kipuka," that is surrounded by relatively barren ground formed by recent lava flows. Kipukas support a diversity of wildlife, and many plant species are found nowhere else on the islands. Two other federally listed endangered plants—Lipochaeta venosa and Stenogyne angustifolia —are found on kipukas.

Distribution

Once found on the islands of Kauai, Molokai, and Hawaii, this species now occurs only on the island of Hawaii. Honohono is known to survive in very low numbers at a single site on Kipuka Kalawamauna on the island of Hawaii. The population is found on a small tract of the Pohakuloa Training Area, which is leased and managed by the U.S. Army.

Threats

The introduction of goats and pigs to Hawaii by European settlers and the subsequent escape of animals into the wild, resulted in severe damage to native Hawaiian plants. Grazing and trampling by feral animals on Kipuka Kalawamauna, have caused the honohono population to decline. Once rooting pigs disturb the soil or grazing goats remove the native ground cover, more aggressive, weedy plants take root and thrive, crowding out many endemics. In the past, this mint has been disturbed by large-scale military maneuvers that are regularly conducted in the area. The greatest damage is caused by tracked vehicles that crush and uproot plants. Policy for the training area already prohibits removal of native plants from the reserve, and the Army has agreed to strengthen its management role in the protection of honohono and other endemics.

Conservation and Recovery

The Army has undertaken a review of its use of the kipuka for military exercises and will restrict unauthorized entry into the habitat area. Further activities in the kipuka are subject to approval by the U.S. Fish and Wildlife Service (FWS) under provisions of the Endangered Species Act. The FWS has removed encroaching plants from some portions of the reserve and recommends a more active feral animal control program. Fire is a great threat to this plant, and a reduction of fires by constructing fire breaks and fire indexes will help protect this species. An exotic fountaingrass, Pennisetum setaceum, competes with the native vegetation and presents a fire hazard as it burns easily.

Contacts

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

Field Office of Endangered Species
U.S. Fish and Wildlife Service
300 Ala Moana Boulevard
P.O. Box 50167
Honolulu, Hawaii 96850

References

Fosberg, F. R., and D. Herbst. 1975. "Rare and Endangered Species of Hawaiian Vascular Plants." Allertonia 1(1):1-72.

Kimura, B. Y., and K. Nagata. 1980. Hawaii's Vanishing Flora. Oriental Publishing, Honolulu.

Sohmer, S. H., and R. Gustafson. 1987. Plants and Flowers of Hawaii. University of Hawaii Press, Honolulu.

U.S. Fish and Wildlife Service. 1979. "Determination That Three Hawaiian Plants Are Endangered Species." Federal Register 44 (211): 62468-62469.

Wooliams, K. R. 1975. "The Propagation of Hawaiian Endangered Species." Newsletter of the Hawaii Botanical Society 14(4):59-68.