Ruth's Golden Aster

Pityopsis ruthii

Description

Ruth's golden aster, Pityopsis ruthii, is a fibrous-rooted perennial with stems about 8 in (20 cm) long. The narrow leaves are covered with silvery hairs. Yellow flowers appear in a loose cluster in late August and September, with seeds developing a few weeks after the flowers fade. The species has also been known by the scientific names Heterotheca ruthii and Chrysopsis ruthii.

Habitat

Ruth's golden aster grows in the cracks and crevices of phyllite boulders along the banks of the Ocoee and Hiwassee Rivers. It is intolerant of shade and dies out quickly when crowded by other vegetation. The plant depends on periodic flooding, which it withstands quite well, to scour away plant competitors.

Distribution

Ruth's golden aster was first collected from Polk County, Tennessee, between 1894 and 1902. No subsequent collections were known and it was thought to be extinct until rediscovered along the Hiwassee River in 1972. A second population was found in 1976 along a short stretch of the Ocoee River.

The Hiwassee River population was been reduced by half (to about 500) from the late 1970s to the late 1980s; by 1992, when the species recovery plan was published, the population had significantly recovered—the plan estimated the existence of between 10,000 and 15,000 individuals in that population. The Ocoee River population contained fewer than 500 plants when the species was listed in 1985. By 1992, that number had barely increased, to 600. Both populations occur within the boundaries of the Cherokee National Forest, although some plants are on Tennessee Valley Authority (TVA) holdings.

Threats

Ruth's golden aster occurs on short reaches of two rivers where the water regimes are controlled by upstream dams operated by the TVA. Construction of the Appalachia Dam in 1943 largely eliminated natural water flows on the Hiwassee River. Water releases from Appalachia Dam have been strictly controlled, causing a significant reduction of the annual flooding and scouring of boulders on which the aster grows. As a result, more competitive species have shaded out some asters.

The Ocoee River population appears to suffer from another extreme—abnormally prolonged flooding during the growing season which drowns plants closest to the river. Although the total volume of water released each year approximates the average annual rainfall in the area, changes of timing of releases have in the past been detrimental to Ruth's golden aster, and continued water management regimes for both dams will need to remain protective of the species if the aster is to recover.

Ruth's golden aster habitat along the Hiwassee River is a popular hiking and fishing area, but so far there has been little harm to the plant. Along the Ocoee River, however, white-water rafters, hikers, and photographers have damaged plants, so recreational use of the area is considered somewhat of a threat to the species.

Degraded water quality in both rivers has also had an impact on Ruth's golden aster. Mining activities at Copperhill, upstream from the Ocoee River dam, have raised sediment levels in the river, harming riverbank species, including Ruth's golden aster. On the Hiwassee River, there have been several upstream spills of toxic sulfuric acid. Releases from Appalachia Dam were made to flush the chemicals from the river, resulting in loss of seed production for the year.

Conservation and Recovery

The 1992 recovery plan for the species notes that the recovery goal for the species is downlisting to threatened and, eventually, delisting altogether, depending on fund availability and the accomplishment of needed recovery activities. Among the recovery actions called for in the plan are studies to determine the species reproductive biology and life history; the determination of habitat requirements; the definition of what constitutes a viable population; and the implementation of management actions needed to ensure the continued existence of self-sustaining populations on the Hiwassee and Ocoee Rivers.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
http://southeast.fws.gov/

References

Cronquist, A. 1980. Vascular Flora of the Southeastern United States. Vol. 1, Asteraceae. University of North Carolina Press, Chapel Hill.

Farmer, R. E., Jr. 1977. "Seed Propagation of Heterotheca ruthii." Castanea 42:146-148.

Semple, J. C., et al. 1980. "Morphological, Anatomical, Habit and Habitat Differences Among the Golden Aster Genera Chrysopsis, Heterotheca, and Pityopsis." Canadian Journal of Botany 58:147-163.

U. S. Fish and Wildlife Service. 1992. "Recovery Plan for Ruth's Golden Aster." U. S. Fish and Wildlife Service, Atlanta.