Achyranthes splendens var.rotundata
|Listed||March 26, 1986|
|Description||Bushy shrub; leaves covered with silvery hairs.|
|Habitat||Semi-arid coastal lowlands.|
|Threats||Shoreline development, competition with introduced plants.|
The shrub Achyranthes splendens var. rotundata grows to a mature height of about 6.5 ft (2 m). It is compact and many-branched. Abundant light green leaves are covered with a silvery down. The plant produces small, inconspicuous flowers that have prominent floral bracts (small leaves at the base of the flower). These leaves were used by native Hawaiians to make their traditional leis.
A. splendens var. rotundata grows in the arid and semi-arid coastal lowlands of the island of Oahu, Hawaii. It requires sandy soils and full sunlight; it does not tolerate shade.
In the 1970s, A. splendens var. rotundata was considered fairly abundant on the island of Oahu in the seaward portions of the Ewa Coral Plain from Barbers Point north to Kaena Point. Specimens collected from two now-extinct populations on Lanai and Molokai islands may be identical with A. splen-dens var. rotundata. If proven correct, this would expand the species' historic range to encompass these islands.
In a short time, Achyranthes splendens var. rotun-data has declined to two fragmented populations, grouped at separate ends of the historic range on Oahu. As of 1986, one population on the military reserve at Kaena Point consisted of only two plants. A second population at Barbers Point consisted of about 400 plants divided into four subgroups. About half of the known surviving plants are located on lands owned by the federal government and managed by the Coast Guard and the Navy. Two smaller colonies are on private lands. Between 1981 and 1986 the number of Achyranthes plants decreased precipitously from 2,000 to an estimated 400 plants. Most of one subpopulation near Barbers Point lighthouse was destroyed by industrial development in 1981. A large colony on federal land was bulldozed inadvertently in 1984. A private estate supported nearly 1,600 plants before being developed for an industrial park in 1985, and by 1986 only about 10% of the plants at this site survived.
Most of the historic range of A. splendens var. rotundata has already been developed for industry, agriculture, housing, or recreation, and the remaining shoreline also faces strong developmental pressures. In addition, introduced plants have made strong inroads into the habitat. One Barbers Point colony is threatened by the parasitic vine, Cassytha filiformis, which forms a dense canopy that smothers all other vegetation. At Kaena Point, an introduced species of Leucaena has spread aggressively. On the Ewa Plains at Barbers Point, thickets of an exotic Pluchea are in direct competition with surviving A. splendens var. rotundata shrubs.
Conservation and Recovery
Since the present populations are exposed to human disturbance, the U.S. Fish and Wildlife Service Recovery Plan has relocated plants to more protected sites and is rehabilitating habitat by controlling exotic plants. Sixty plants were relocated in 1985 from Barbers Point to a protected site. The historic range on Oahu and potential habitat on the islands of Lanai and Molokai will be surveyed in an attempt to locate additional plants or populations.
U.S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N.E. 11th Ave.
Portland, Oregon 97232-4181
Nagata, K. M. 1981. "Status Report onAchyranthes splendens var. rotundata." Contract Report #14-16-001-79096. U.S. Fish and Wildlife Service, Honolulu, Hawaii.
St. John, H. 1979. "Monograph of the HawaiianSpecies of Achyranthes (Amaranthaceae): Hawaiian Plant Studies 56." Pacific Science 33(4): 333-350.