No Common Name
|Listed||October 29, 1991|
|Description||Upright plant with leathery, lobed leaves and clusters of yellow flowers.|
|Habitat||Well-drained, dry slopes.|
|Threats||Feral goats, fire, erosion, alien plant species, low numbers.|
Sanicula mariversa is an upright herb in the parsley family that reaches a height of 16-28 in (40-70 cm). Leathery, lobed, heart-to kidney-shaped leaves grow from the base, becoming smaller and more deeply lobed as they ascend the stem. Male and hermaphroditic yellow flowers appear in clusters of 10-20 at the stem end or from the leaf axils.
The egg-shaped fruit is covered with hooked prickles and contains two seeds. This species flowers from February through May, and fruits can be found until August. Dry fruits remain on infructescences for a long time and may persist beyond August.
S. mariversa is found on well-drained dry slopes at elevations of 2,500-2,800 ft (760-850 m). Associated plant species include Hamakua pamakani or spreading mist flower (Ageratina riparia ), kawelu (Eragrostis variabilis ), and 'ohi'a (Metrosideros polymorpha ).
S. mariversa, discovered in 1981 in the Waianae Mountains of Oahu, has not been found on any of the other Hawaiian islands. Its historical appearances occurred from Makua-Keaau Ridge to Kaluaa-Lualualei Summit Ridge in the central area of the mountains.
The species survives at two sites at Makua-Keaau Ridge on state land. These populations, less than 0.5 mi (0.8 km) apart, together contained less than 75 plants in 1997.
The major threats to S. mariversa are habitat degradation by feral goats, fire, erosion, competition from Christmasberry and molasses grass, trampling by humans on or near trails, and the risk of extinction due to the small number of populations.
Fire is a special danger to S. mariversa populations that occur near the U. S. Army's Makua Military Reservation and Schofield Barracks Military Reservation. Within a 14-month period from 1989 to 1990, 10 fires resulted from weapons practice on the reservation. In order to minimize damage from fires, the army has constructed firebreaks between the target areas and the surrounding forest.
Conservation and Recovery
The U. S. Army has adopted a fire management plan that includes realigning targets and establishing firebreaks. Nevertheless, a coordinated fire protection plan for endangered plant species on state forest reserves (Makua Keaau) and federal lands (the army's Makua Military Reservation) needs to be developed and implemented. The army has also conducted some erosion control that has helped to stabilized the S. mariversa population on Makua-Keaau. The completion of a boundary fence on the south and southeast perimeter of Makua Valley and continued goat control efforts should protect this species from further goat damage.
S. mariversa is being successfully propagated at the National Tropical Botanical Garden and the State of Hawaii's Division of Forestry and Wildlife's mid-elevation Nike site at Pahole.
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 Remote Islands Ecological Services Field Office
300 Ala Moana Blvd., Room 3-122
P.O. Box 50088
Honolulu, Hawaii 96850-5000
Telephone: (808) 541-3441
Fax: (808) 541-3470
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.