Carter's Panicgrass

Panicum fauriei var. carteri

Description

Carter's panicgrass, Panicum fauriei var. carteri, is an annual grass, 8 in (20 cm) or more high, with narrow blades and few seed heads borne on hair-like branches. Plants flower during and immediately after the winter rains. New growth is mostly from seed.

Habitat

This plant is known from the dry lowlands of tiny Mokolii Island (known as Chinaman's Hat), off the coast of Oahu near Kualoa Point. The island, with an area of roughly 4 acres (1.6 hectares), provides a severe habitat-strong sunlight, low rainfall, and constant exposure to salt spray.

The soil is gravelly and formed mostly from basalt. Salinity in the soil benefits panicgrass by limiting the spread of its plant competitors.

Distribution

Carter's panicgrass appears to be a native of Mokolii Island and was probably never widespread. This species and several close relatives in the Hawaiian islands are thought originally to have derived from a single stock. The species was first discovered in 1941 and was then believed extinct until 1976, when 24 individuals were found in a small area of Mokolii Island. Numbers can vary drastically from year to year, depending on the amount of rainfall. The largest number of plants ever observed was slightly more than 200 in a particularly wet year. In some years, surveys have not located any plants at all.

Threats

Carter's panicgrass is endangered by its low numbers and limited distribution. In addition, the habitat is vulnerable to human disturbance. The island is a part of Kualoa Regional Park and is accessible to park visitors, who reach it by wading through shallow water. In recent years recreational use has increased, causing incidents of trampling, vandalism, and fire.

The island is also vulnerable to the introduction of non-native plants. In 1983, an unauthorized planting of several coconut trees for landscaping purposes generated alarm among botanists. Such plantings could inadvertently introduce exotic species, such as Henry's crabgrass, that could crowd out the panicgrass.

Conservation and Recovery

Critical habitat has been designated to include the entire island of Mokolii. The city of Honolulu has designated the island as a wildlife sanctuary.

Contact

Regional Office of Endangered Species
U. S. Fish and Wildlife Service
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232
http://pacific.fws.gov/

Reference

U.S. Fish and Wildlife Service. 1983. "Rule to List Panicum carteri (Carter's panicgrass) as an Endangered Species." Federal Register 48 (198): 46328-46332.