No Common Name
|Listed||October 29, 1991|
|Description||Erect shrub with elliptic leaves; male and female flowers on separate plants.|
|Habitat||Slopes, ledges, and gulches in moist forest.|
|Threats||Feral pigs and goats, alien plant species.|
Neraudia angulata is an erect shrub of the nettle family that grows to 10 ft (3 m) in height. The elliptic leaves, 3-6 in (7.5-15 cm) long, are slightly hairy above and moderately hairy below. Male and female flowers occur on different plants. N. angulata flowers and fruits from early spring to summer; fruits then mature in about a month. Two varieties of this endangered plant are recognized, the prime physical difference between them being that N. angulata var. angulata has untoothed leaves and N. angulata var. dentata has toothed leaves.
N. angulata grows on slopes, ledges, or gulches in diverse moist forest dominated by lama (Diospyros sandwicensis ) at elevations between 1,200 and 2,700 ft (365 and 823 m). Associated species include aulu (Sapindus oahuensis ), Christmasberry (Schinus terebinthifolius ), and olopua (Nestegis sandwicensis ).
N. angulata was known historically from Kaluakauila Gulch nearly to Puu Manawahua, a distance running almost the entire length of the Waianae Mountains. This species is currently known from Kaluakaulla Gulch along Makua-Keaau Ridge to Makaha-Walanae Kai Ridge on Federal, state, and private land. The 15 extant populations, all within an area of about 3-11 mi (5-17.5 km), contained approximately 110 individuals in 1997. Except for two populations that contained between 20 and 50 individuals, all of the remaining populations had fewer than 12 individuals each.
The main threats to N. angulata are habitat degradation by feral pigs and goats and competition with aggressive alien plant species. Pigs, which are managed by the state as game animals, have had a major effect on the native flora. Their rooting destroys plants and opens the habitat to invasive species. They also help spread alien plants by carrying seeds on their bodies and in their feces. Feral goats have had similar detrimental effects and are able to reach areas inaccessible to pigs.
Non-native plants threaten almost all native Hawaiian flora, especially rare species. N. angulata is directly threatened by Christmasberry, molasses grass (Melinis minutiflora ), and strawberry guava (Psidium cattleianum ).
Some plants of this species lie near the U.S. Army's Makua Military Reservation and Schofield Barracks. Within a 14-month period from 1989 to 1990, 10 fires resulted from weapons practice on the reservation. A fire in July 1989 may have destroyed a N. angulata population.
With only 15 known populations, the species is extremely vulnerable to extinction through unpredictable human or natural events.
Conservation and Recovery
The U. S. Army has adopted a fire management plan that includes realigning targets and establishing firebreaks in Makua Military Reservation. These actions may aid in protecting this species from the threat of fire. The completion of the boundary fence on the south and southeast perimeter of Makua Valley and continued goat control efforts, though limited, should also help to protect this species from further goat damage.
The National Tropical Botanical Garden is currently propagating N. angulata.
Pacific Joint Venture
300 Ala Moana Boulevard, Room 3-122
P.O. Box 50167
Honolulu, Hawaii 96850-5000
U.S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N.E. 11th Ave.
Portland, Oregon 97232-4181
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.
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.
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.