Kamakahala (Labordia tinifolia var. lanaiensis)
Labordia tinifolia var . lanaiensis
|Listed||September 3, 1999|
|Description||A tropical shrub or short tree.|
|Habitat||Lowland, mesic, tropical forest.|
|Threats||Habitat loss, browsing by introduced mammalian herbivores, and habitat damage and competition associated with invasive alien plants.|
The kamakahala is a shrub or small tree that grows as tall as 49 ft (15 m). Its stems branch regularly into two forks of approximately equal size. The leaves are medium-to dark-green, oval to narrowly oval in shape, 1.5-8.3 in (3.8-21 cm) long, and 0.6-2.9 in (1.4-7.3 cm) wide. The leaf petiole is 0.9-1.6 in (2.2-4.0 cm) long, and is subtended by fused stipules that form a sheath around the stem 0.04-0.20 in (1-4 mm) long. Each flower cluster contains 3 to 19 flowers, and the entire inflorescence is pendulous and hangs from a stalk 0.4-0.8 in (9-22 mm) long. The corolla is colored pale yellowish-green or greenish-yellow, and is narrowly urn-shaped and 0.2-0.7 in (6.5-19 mm) long. The ripe fruit is broadly oval, 0.3-0.7 in (8-17 mm) long, 2-to 3-valved, and has a beak 0.02-0.06 in (0.5-1.5 mm) long. The seeds are brown and about 0.06 in (1.8 mm) long. This variety differs from the other two varieties of Labordia tinifolia and other species in this endemic Hawaiian genus in having larger capsules and a smaller corolla.
The habitat of the kamakahala is lowland, mesic, tropical forest, associated with such native species as Dicranopteris linearis and Scaevola chamissoniana.It occurs at elevations between 2,500 and 3,000 ft (760 and 915 m).
The kamakahala is a locally evolved (or endemic) species that is only known from Lanai, Hawaii. The Hawaiian archipelago has an extremely large fraction of endemic species; about 89% of the indigenous flowering plants occur nowhere else in the world. The kamakahala was historically known from the entire length of the summit ridge of Lanai-hale, on the island of Lanai.
The kamakahala is threatened by browsing by introduced mammalian herbivores, especially axis deer (Cervis axis ). It is also threatened by habitat damage and competition associated with several alien plants, such as strawberry guava (Psidium cattleianum ), firetree (Myrica faya ), and Christmasberry (Schinus terebinthifolius ). Because it occurs in only a single, relatively small population, it is also potentially threatened by the deleterious effects of inbreeding and catastrophic disturbance caused by a hurricane or wildfire. The kamakahala is now known from only one population at the southeastern end of the summit ridge of Lanaihale. This population occurs on privately owned land and totals an estimated 300 to 1,000 scattered individuals.
Conservation and Recovery
The only surviving population of the kamakahala is located on privately owned land, and so it is potentially at risk from disturbance or other human actions. Conservation of the endangered kamakahala requires that its critical habitat be protected and managed to reduce the threats posed by non-native herbivores and alien plant competitors. This would best be achieved by acquiring the privately owned habitat and designating it as a protected area, or by negotiating a conservation easement. In addition, the surviving population of the kamakahala should be monitored against future change. Research should be undertaken to develop a better understanding of the degrading influences faced by the endangered plant, and of ways of mitigating those effects. Work should also be undertaken on propagation of the rare plant in captivity, with a view to producing stock for out-planting into the wild.
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
U. S. Fish and Wildlife Service
Pacific Islands Ecoregion, Pacific Islands Fish and Wildlife Office
300 Ala Moana Boulevard, Room 3-122
P. O. Box 50088
Honolulu, Hawaii 96850-5000
Telephone: (808) 541-3441
Fax: (808) 541-3470
U. S. Fish and Wildlife Service. 3 September 1999. "Endangered and Threatened Wildlife and Plants: Final Endangered Status for 10 Plant Taxa From Maui Nui, Hawaii." Federal Register 64 (171).