No Common Name
|Listed||October 10, 1996|
|Description||Many-branched shrub with stalkless flowers.|
|Habitat||Lowland dry forest.|
|Threats||Habitat degradation and destruction by cattle and feral goats, competition with alien plant species, naturally occurring events.|
Achyranthes mutica is a many-branched shrub of the amaranth family (Amaranthaceae) with stems ranging from 12 to 24 in (30.5 to 60.9 cm) in length. The opposite leaves, usually 1.3-1.6 in (3.3-4.1 cm) long and 0.6-0.8 in (1.5-2.0 cm) wide, are inversely egg-shaped to elliptic or inversely lance-shaped. The stalkless flowers are arranged in spikes, 0.2-0.6 in (5.1-15.2 mm) long, directly attached to the main flower axis. The apetalous flowers are perfect (containing both female and male parts). The sepals are of unequal length, sharply pointed at the tips, and range from 0.1 to 0.2 in (0.25 to 0.51 cm) long. This species is distinguished from others in the genus by the shape and size of the sepals and by the short and congested characteristics of the spike. A. mutica was first described by Asa Gray in 1867 from a specimen collected on Kauai between 1851-55 by Ezechiel Jules Remy, a French naturalist and ethnologist. A. nelsonii is considered to be synonymous with A. mutica by the authors of the current treatment of Hawaiian members of the family.
A. mutica plants grow at elevations of approximately 3,030 ft (923.5 m) in Acacia koaia (koai'a) lowland dry forest. Dodonaea viscosa ('a'ali'i), Myoporum sandwicense (naio), Nestegis sandwicensis (olopua), Osteomeles anthyllidifolia ('ulei), and Sophora chrysophylla (mamane) accompany A. mutica.
A. mutica was known historically from three collections from Kauai and Hawaii, at opposite ends of the main archipelago. This species is known today only on private land on Hawaii Island from the Keawewai Stream area, the south slope of Puu Loa in the Kohala Mountains, and Lanikepu Gulch. These populations harbored from 30 to 50 plants in 1997.
The primary threats to A. mutica are habitat degradation and destruction by cattle and feral goats, competition with alien plant species, and a risk of extinction from naturally occurring events like landslides and hurricanes. This taxon may experience reduced reproductive vigor due to the small number of existing individuals left in the populations. Cattle, deer, and goat predation is a possible threat for this plant. The only known population ofA. mutica in the Keawewai Stream area on the island of Hawaii is presently threatened by goats and cattle-ranching activities.
Collecting for scientific or horticultural purposes and visits by individuals avid to see rare plants are potential threats to A. mutica. A. mutica is threatened by common guava, Ageratina riparia, Kikuyu grass, hairy horseweed, and panini.
Conservation and Recovery
A. mutica has been successfully propagated at the National Tropical Botanic Gardens where, in 1997, more than 500 seeds were in storage and about 20 plants were in cultivation. A fence constructed by one landowner proved successful in protecting one plant from grazing cattle in an area called Kalopi. The construction of additional exclosures is recommended to reduce the impact from domestic cattle and feral goats. Removal of cattle to locations away from the preferred habitat of A. mutica is recommended, as are various methods of feral goat removal. The implementation of such goat removal measures has proven successful elsewhere in the state.
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. 10 October 1996. "Determination of Endangered or Threatened Status for Fourteen Plant Taxa From the Hawaiian Islands." Federal Register 61 (198): 53108-53124.