Stenogyne campanulata

No Common Name

Description

Stenogyne campanulata is a vine in the mint family with square and hairy stems. The hairy, serrated leaves are broadly ovate, about 2 in (5 cm) long, and 1 in (2.5 cm) wide. The white tubular flowers, about 0.5 in (1.3 cm) long, have short purple lobes and occur in clusters of six at the leaf axils. Although the fruits have never been described, those of all other members of the genus are fleshy nutlets. It is distinguished by its large, broadly bell-shaped calyces that nearly enclose the relatively small, straight corollas, as well as by small calyx teeth that are half as long as wide.

Habitat

S. campanulata is one of large number of species endemic to the Kokee area in the northwestern part of the Hawaiian island of Kauai. This area is roughly encompassed by the eight-square-mile Kokee State Park. S. campanulata is found only on the nearly vertical rock face of north-facing cliff below the rim of Kalalau Valley, just north of Kokee State Park, at an elevation of about 3,700 ft (1,127.7 m).

Five other plant species endemic to the Kokee region are listed as endangered: Chamaesyce halemanui, Dubautia latifola, Poa siphonoglossa, Poa sandvicensis, and Xylosma crenatum.

Distribution

S. campanulata was discovered in 1986 at the Kalalau Valley cliff site in Na Pali Coast State Park. It has not been found at any other location.

Known only from a single location on state land, the S. campanulata population is estimated at about 50 plants that are confined to an area of about 500 sq ft (46.5 sq m).

Threats

The primary threat to the survival of S. campanulata is habitat disturbance by feral goats and pigs. Goats consume plants and eliminate native vegetation, allowing the expansion of alien plant species, especially daisy fleabane. The fact that S. campanulata now occurs only on a virtually inacessible cliff site suggests that it may have been eliminated from more accessible sites by browsing goats.

Plum trees were planted in Kokee State Park in the 1930s, providing a food source that attracted feral pigs. Logging activities and the construction of ditch and water diversion systems for irrigation had by this time created a network of paths, trails, and roads that gradually allowed pigs to penetrate into previously inaccessible habitats. It is in these areas that pigs have done so much harm to the native species there, possibly including now-extirpated groups of S. campanulata.

In addition to these predictable threats, the low number of existing S. campanulata plants and the fact that they are concentrated in a single population puts the species at risk of extinction through unpredictable events.

Conservation and Recovery

S. campanulata has been successfully propagated and then cultivated by National Tropical Botanical Garden, where seeds are also held in storage.

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/

U.S. Fish and Wildlife Service
300 Ala Moana Boulevard, Room 6307
P.O. Box 50167
Honolulu, Hawaii 96850
(808) 541-2749

References

Cuddihy, L.W., and C.P. Stone. 1990. Alteration of Native Hawaiian Vegetation: Effects of Humans, Their Activities and Introductions. Cooperative National Park Resources Study Unit, University of Hawaii Press, Honolulu.

Macdonald, G.A., A.T. Abbott, and F.L. Peterson.1983. Volcanoes in the Sea. 2d ed. University of Hawaii Press, Honolulu.

Stone, C. P., and J.M. Scott, eds. 1985. Hawai 'i's Terrestrial Ecosystems: Preservation and Management. Cooperative National Park Resources Study Unit, University of Hawaii Press, Honolulu.

U.S. Fish and Wildlife Service. 13 May 1992. "Endangered and Threatened Wildlife and Plants; Determination of Endangered or Threatened Status for Six Plants from the Kokee Region, Island of Kauai, Hawaii." Federal Register 57 (93): 20580-20587.

Wagner, W.L., D.R. Herbst, and S.H. Sohmer. 1990. Manual of the Flowering Plants of Hawai 'i. University of Hawaii Press and Bishop Museum Press, Honolulu.