Gouania vitifolia

No Common Name

Description

Gouania vitifolia is a climbing shrub or woody vine in the buckthorn family with tendrils. Leaves are papery in texture with a moderate to dense covering of soft, short hairs on both surfaces. The leaves, elliptic to broadly oval in outline with toothed or lobed margins, are 1.2-3.2 in (3.1-8.1 cm) long by 0.8-1 in (2-2.5 cm) wide. Flowers are arranged in axillary spikes 0.3-2.8 in (0.8-7.1 cm) long. The flowers are small with sepals and petals ranging from 0.03-0.04 in (0.08-0.1 cm) in length. Both the sepals and petals are white. The two-or three-winged fruit are about 0.4 in (1 cm) long. Seeds are oval, glossary, dark brown, and about 0.1-0.2 in (0.3-0.5 cm) long. In winter and spring the main vine produces new young side shoots that soon die. Plants have been observed flowering from late November to January, but flowering probably depends on precipitation. Although plants have been observed flowering, this species has never been observed fruiting; it is unknown whether the flowers produce both pollen and ovules. This species is the only Hawaiian member of the genus with tendrils and toothed leaf margins.

Habitat

Although there is not much information, data from herbarium labels indicate that G. vitifolia prefers dry, rocky ridges and slopes in dry shrub-land or dry to mesic forests at an elevation of about 2,000 ft (610 m). Associated plant species include Christmasberry, strawberry guava, kukui, huehue haole, and mamaki.

Distribution

G. vitifolia had historical occurrences from West Maui; the Kau District of the island of Hawaii; and the northwestern portion of the Waianae Mountains in Makaleha, Keaau, and Waianae Kai valleys. However, it is currently known on Oahu from only a single population discovered in 1990 on the slopes of Waianae Kai Ridge on state-owned land. This occurrence had eight individuals in 1997; growing close to one another, these plants are grouped in two patches in a forest of mostly naturalized alien plants, and they may represent clones of a single individual. Two additional populations of 18 total individuals were discovered on Hawaii within the Manuka Natural Area Reserve in 1998.

Threats

The major threats to G. vitifolia on Oahu are competition from alien plants such as huehue haole, strawberry guava, and Christmasberry and fire. On Hawaii this plant is threatened by common guava, sweet granadilla (Passifiora ligularis ), and banana poka. All populations are threatened by habitat destruction by feral pigs; all populations could suffer extinction or reduced reproductive vigor due to the small number of extant individuals, many of whom may be genetically identical.

Conservation and Recovery

Asexual propagation (via cuttings) and weeding was conducted in the area of the single population by the Division of Forestry and Wildlife during February 1997. This species is also being propagated at the National Tropical Botanical Garden.

The Big Island population located at Olopua kipuka is being fenced, and individuals from both Big Island populations are in propagation at the Volcano Plant facility.

Contact

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

Reference

U.S. Fish and Wildlife Service. 27 June 1994. "Endangered Status for Three Plants from the Waianae Mountains, Island of Oahu, HI." Federal Register 59:32933-32939.