Kamakahala (Labordia triflora)
|Listed||September 3, 1999|
|Description||A tropical climbing shrub.|
|Habitat||Lowland, mesic, tropical forest.|
|Threats||Habitat loss, browsing by introduced mammalian herbivores, and competition associated with invasive alien plants.|
The kamakahala is a climbing woody shrub or vine. 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 to 2.9 in (1.4-7.3 cm) wide. The leaf petiole is 0.04-0.10 in (1-3 mm) long, and is subtended by fused stipules that form a sheath around the stem. Each flower cluster contains 3 to 19 flowers, and the entire inflorescence is pendulous and hangs from a stalk 1.6 -2 in (40-50 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 species differs from others in the endemic Hawaiian genus Labordia in having climbing stems.
The kamakahala occurs in mixed lowland, mesic, tropical forest, at an elevation of about 2,600 ft (800 m). Associated species include the alaa (Pouteria sandwicensis ), the endangered haha (Cyanea mannii ), and the ohe (Tetraplasandra sp.).
The kamakahala is a locally evolved (or endemic) species that is only known from Molokai, 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 is only known from two sites.
The principal threats to the kamakahala include habitat degradation and destruction caused by introduced mammalian herbivores (especially pigs, goats, and seed-eating rats), and competition with the alien plant Christmasberry (Schinus terebinthifolius ). Because it occurs in only a single tiny 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 location, in Kua Gulch on Molokai. Only 10 individuals are known at this site, all occurring on privately owned land. Only two of these individuals are male plants, and the rest females.
Conservation and Recovery
The only surviving population of the kamakahala is located on privately owned land, and is potentially at risk from human disturbance or other actions. Conservation of this endangered plant requires that its critical habitat be protected and managed to reduce the threats posed by non-native mammals 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 tiny surviving population of the kamakahala must 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 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 Building
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
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):48307-48324.