|Listed||October 10, 1996|
|Family||Gesneriaceae (African violet)|
|Description||Unbranched, fleshy, and erect or ascending shrub; bears white flowers.|
|Habitat||On steep slopes or cliffs near streams or waterfalls in lowland or montane wet forest or shrubland dominated by 'ohi'a or a mixture of 'ohi'a and uluhe.|
|Threats||Competition with alien plants.|
Cyrtandra cyaneoides, or mapele, a shrub of the African violet family (Gesneriaceae) about 3.3-4.3 ft (1-1.3 m) tall, is unbranched, fleshy, and erect or ascending. The opposite, symmetrical, egg-shaped leaves are fleshy and leathery, 16-22 in (40.6-55.8 cm) long and 9-14 in (22.8-35.5 cm) wide. The upper surface of the toothed leaves is wrinkled with impressed veins and sparsely covered with long hairs. The lower surface has raised veins and is sparsely covered with hairs. The leaf stalks are 1.8-5.5 in (4.6-14 cm) long and winged. The white flowers, covered with shaggy brown hairs, arise from the leaf axils in small dense clusters. The corolla tube (fused petals) is a narrow funnel form, curved near the middle, about 1 in (2.5 cm) long, and hairless. The corolla lobes are elliptic and about 0.3 in (0.75 cm) long. The bilaterally symmetrical calyx is spindle-shaped in bud and about 1-1.4 in (2.5-3.5 cm) in length when the flower is fully open, although it falls off after the flower matures. The fruit is an egg-shaped berry which is covered with shaggy hairs, at least when young.
Although poorly known, C. cyaneoides is a very distinctive species. It differs from others of the genus that grow on Kauai by being a succulent, erect or ascending shrub with a bilaterally symmetrical calyx that is spindle-shaped in bud and falls off after flowering. It also has the distinguishing characteristics of leaves with wrinkled upper surfaces and berries with shaggy hairs.
C. cyaneoides typically grows on steep slopes or cliffs near streams or waterfalls in lowland or montane wet forest or shrubland dominated by 'ohi'a or a mixture of 'ohi'a and uluhe. Associated species include Boehmeria grandis ('akolea), Pipturus sp. (mamaki), 'olapa, 'uki, Athyrium sp., and Hedyotis sp. (manono).
C. cyaneoides was originally known only from the type collection made at Kaholuamanu 80 years ago, along the trail to Waialae Valley on the island of Kauai. Botanists from National Tropical Botanical Garden discovered a population of 50-100 individuals in 1991 at Namolokama above Lumahai Valley. Four additional populations of 350-400 total individuals were discovered over the next two years: one plant on the Makaleha Plateau, more than 300 plants in Wainiha Valley, one plant in upper Waioli Valley, and an unknown number of plants in Koaie Canyon. The five known populations occur at elevations between 1,800 and 4,000 ft (548.6 and 1,219.2m) elevation on private and state land.
The major threat to C. cyaneoides is competition with the alien plants fireweed, Hilo grass, thimbleberry, Deparia petersenii, and Drymaria cordata (pip ili). Fireweed, Hilo grass, and thimbleberry all threaten the Makaleha Mountains population of C. cyaneoides. Pipili, a pantropical annual herb now naturalized in moist and shaded sites on Kauai and four other islands, also threatens the Makaleha Mountains population. Deparia petersenii, a perennial fern capable of forming a thick groundcover, often competes for space with this endangered plant. All these plants degrade C. cyaneoides habitat; together they provide formidable competition for this native plant.
Other agents and conditions that threaten this species are probable rat predation of the fruit, possible extinction through reduced reproductive vigor and destructive natural events because of the small number of its known populations, and the possible future incursion of feral pigs into the upper Wainiha Valley from where they have been reported in the lower valley. Erosion, landslides, and rock slides— destructive episodes that kill individual plants and destroy habitat—are especially dangerous to the Makaleha Mountains and upper Waioli Valley populations of C. cyaneoides, each of which has only one individual.
Conservation and Recovery
In 1997, National Tropical Botanical Garden held more than 1,000 seeds in storage.
U.S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N.E. 11th Ave.
Portland, Oregon 97232-4181
U.S. Fish and Wildlife Service. 1988. "Kauai II: Addendum to the Recovery Plan for the Kauai Plant Cluster." U.S. Fish and Wildlife Service, Portland, Oregon. 84+ pp.