Wawa'iole

Huperzia mannii

Description

Wawa'iole (Huperzia mannii) is a pendent epiphyte of the clubmoss family (Lycopodiaceae) with clustered red stems 1.6-3.9 in (4-9.8 cm) long and 0.04 in (1 mm) thick. The leaves, arranged in three rows on the stem, are pointed, flat, and lanceolate. Fruiting spikes branch four to six times and are 7-9 in (17.5-22.5 cm) long and 0.4-0.6 in (1-1.5 cm) wide. The spikes possess 0.04 in (1 mm) long bracts arranged in two to four ranks that function to conceal spore capsules.

Habitat

H. mannii typically grows on plants such as 'ohi'a or Acacia koa in mesic to wet montane 'ohi'a/koa forests on Maui and the island of Hawaii. Associated plant species include pilo, 'olapa, kawa'u, and kolea. Additional associates on the island of Hawaii are mamane and kaluaha.

Distribution

Historically, Huperzia mannii was known from Walakoali on Kauai, Haelaau and Hanaula on West Maui, and Hawaii Island. The first collection of this very slender species was made on Maui before 1868.

The majority of remaining Huperzia mannii is believed to occur on East Maui, where it was first recorded in 1976 in the Healani region in the Kipahulu Forest Reserve at about 4,200 ft (1,260 m) elevation. A 1982 estimate of the Healani population was 50 individuals in the two colonies

Two populations of Huperzia mannii are currently known from the Kahikinui Forest Reserve on East Maui. Six individuals growing on the trunks of two Acacia Koa trees were discovered in 1981 within the Reserve in Manawainui Gulch at 5,300 ft (1,590 m) elevation. Art Medeiros and Mahealam Kaiaokamalie, discoverers of the second Reserve population in 1995, observed seven individuals growing on the trunks of Acacia koa trees in an unnamed gulch west of Manawamui Gulch at 4,880 ft (1,460 m) elevation.

A fourth East Maui population was discovered in 1992 at 2,000-2,500 ft (600-750 m) elevation on the southern rim of Kipahulu Valley, at a site referred to locally as "Cable Ridge." This occurrence is partially within Haleakala National Park, but it also extends onto adjacent state and private land. "Cable Ridge" has easily the largest population of the species, with several hundred individuals growin on an area of about 650 acres (1,625 hectares). At least a few individuals of Huperzia mannii occur in a fifth population at Lihau and Puu-kukui on West Maui. It is also sparingly present in a sixth population on state and private land at Laupahoehoe Natural Area Reserve on the island of Hawaii. The total number of extant individuals was thought to be fewer than 300 in 1995.

Threats

The major threats to Huperzia mannii are habitat degradation caused by pig and cattle predation and trampling; competition for space, light, water, and nutrients by naturalized exotic species, especially prickly Florida blackberry; and the small number of remaining individuals.

Conservation and Recovery

An exclosure was constructed in 1990, using barbed-wire and woven-wire, to protect the Manawainui Gulch population of Huperzia mannii in the Kahikinui Forest Reserve, as well as associated species. This fence construction was a cooperative effort between the Native Hawaiian Plant Society and the Maui Division of Forestry and Wildlife. Living Indigenous Forest Ecosystems has fenced the second Kahikinui population of Huperzia mannii The "Cable Ridge" population of Huperzia mannii is easily the largest, far exceeding the combined number of individuals of all other known populations. Because of the size of this population of Huperzia mannii and the quality of surrounding habitat, protection of this population is the most important step for the long-term conservation of the species. Protection involves construction of a woven-wire ex-closure and elimination of feral pigs that are now common and destructive in the area. Control of aggressive alien species like the tree fern Cyathea cooperi, which is common and invasive in lower elevation areas of the "Cable Ridge" population, may be necessary in some parts of this occurrence.

The two colonies are currently unprotected from feral goats and pigs. Continued degradation of this site will cause the loss of native tree species and conversion to alien grasslands. Without protection, the continued loss of Acacia koa and Dodonaea viscosa trees, which host Huperzia mannii at this site, will cause decline and eventual extirpation of these populations. Protection by woven-wire fence exclosures in this area has demonstrated potential for increasing cover and density of native tree species.

Contact

U. S. Fish and Wildlife Service
Office of the Regional Director
Eastside Federal Complex
911 N.E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6118
Fax: (503) 231-2122
http://pacific.fws.gov/

Reference

U.S. Fish and Wildlife Service. 1997. "Recovery Plan for the Maui Plant Cluster." U.S. Fish and Wildlife Service, Portland, Oregon.