Ha'iwale

Cyrtandra limahuliensis

Description

Ha'iwale (Cyrtandra limahuliensis ) is an un-branched or few-branched shrub in the African violet family (Gesneriaceae) that can reach a height of 5 ft (1.5 m). The opposite, elliptic leaves are usually 6-12 in (15.2-30.4 cm) long and 2.0-4.7 in (5.1-11.9 cm) wide. The upper surface of the toothed leaves is moderately hairy and the lower surface, with deep veins, is moderately or densely covered with yellowish brown hairs. Single downy flowers are borne in the leaf axils. The slightly curved corolla tube of fused petals barely extends beyond the calyx that encloses long berries at maturity. This species is distinguished from others of the genus by hairy leaves, especially on the lower surfaces; the usually symmetrical calyx is also tubular or funnel-shaped and encloses the fruit at maturity, and the flowers are borne singly.

Habitat

C. limahuliensis typically grows along streams in lowland wet forests at elevations between 800-2,850 ft (243-868 m). Associated plant species include hame, ho'i'o, olomea, uluhe, 'ape'ape and kopiko.

Distribution

Historically, C. limahuliensis was known on Kauai from Wainiha Valley, Limahuli Valley, and near Kilauea River. One population remains in Wainiha Valley and 11 others exist on private and state land at Limahuli Valley, Waipa Valley, Mount Kahili, the north fork of Wahiawa stream, along Anahola stream, Waioli Valley, and near Powerline Trail.

The 12 known populations of 2,800-3,000 total individuals, distributed over a 13 by 18 mi (20.9 by 28.9 km) area, range in size from solitary shrubs to large populations of over 1,000 plants. The largest populations occur in the upper Waioli Valley, where three populations total at least 2,100 individuals. Another location with hundreds or perhaps thousands of plants is limited to the 0.25 sq mi (0.6 sq km) area along the north fork of the Wailua River. Other botanists familiar with this population believe it to number no more than 500 individuals.

Threats

The major threat to C. limahuliensis is competition from invasive alien plants, especially strawberry guava. Each population faces additional threats. Competition with introduced Hilo grass and Melastoma candidum threaten the Mount Kahili population; competition with common guava and habitat degradation by feral pigs menace the Anahola stream population; and competition with yellow ginger is a problem for the Wainiha Valley population. Individuals of the Wailua stream population are situated at the base of a steep cliff and are vulnerable to natural landslides. Thimbleberry, Oriental hawksbeard, and fireweed threaten the Waioli Valley populations. Hurricanes are also a potential threat, but most of the plants have grown back vigorously since Hurricane Iniki.

Conservation and Recovery

C. limahuliensis is only known to occur in three areas of lowland wet forest on Kauai. These consist of about 12 known populations occurring within an area of only 13 by 18 mi (20 by 30 km) and ranging in size from solitary plants to more than 1,000 individuals (the total population is 2,800-3,000 plants). All the critical habitats of this rare shrub should be protected. However, the highest priority should be given to the habitats of three populations in the upper Waioli Valley that support more than 2,100 individuals and another along the north fork of the Wailua River with about 500 plants. In addition to protecting the natural habitat of C. limahuliensis from physical destruction, these areas must be managed to reduce the damage caused by invasive non-native plants, especially shrubs such as strawberry guava (Psidium cattleianium ) and Indian rhododendron (Melastoma candidum ), and herbaceous plants such as Hilo grass (Paspalum conjugatum ), yellow ginger (Hedychium flavescens ), and thimbleberry (Rubus rosifolius ). Some populations are also threatened by feeding and disturbance by feral pigs, which should be eliminated from the habitat. The C. limahuliensis has been propagated in captivity, and stock could be made available for out-planting to supplement the reproduction of wild populations. Additional fieldwork should be undertaken to try discover new populations, to monitor the sizes of known ones, and to better understand the ecological factors affecting the distribution and abundance of the rare shrub. This information is needed to guide the conservation of the C. limahuliensis and the management of its natural habitat.

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
Telephone: (503) 231-6121
http://pacific.fws.gov/

Senior Resident Agent Office
U.S. Fish and Wildlife Service
300 Ala Moana Boulevard, Room 7-235
P.O. Box 50223
Honolulu, Hawaii 96850-5000
Telephone: (808) 541-2681
Fax: (808) 541-3062

Reference

U.S. Fish and Wildlife Service. 25 February 1994. "Endangered and Threatened Wildlife and Plant; Determination of Endangered or Threatened Status for 24 Plants from the Island of Kauai, HI." Federal Register 59 (38): 9304-9329.

U.S. Fish and Wildlife Service. 1995. "Recovery Plan for the Kauai Plant Cluster." U.S. Fish and Wildlife Service, Portland, OR.