Large-flowered Skullcap

views updated

Large-flowered Skullcap

Scutellaria montana

StatusEndangered
ListedJune 20, 1986
FamilyLamiaceae (Mint)
DescriptionLong-stemmed herb with oblong leaves and blue and white flowers.
HabitatRocky slopes in old-growth hardwood forests.
ThreatsLogging, clear-cutting to support agriculture.
RangeGeorgia, Tennessee

Description

The large-flowered skullcap, Scutellaria montana, is a stocky, erect herb with square stems that grow to a mature height of about 22 in (55 cm). Opposite leaves are oblong, up to 3 in (8 cm) in length. Attractive blue and white flowers bloom in May and early June. The fruit, a light brown nutlet, matures in late June or early July.

Habitat

The skullcap grows in dry to slightly moist rocky slopes within undisturbed, mature oak and hickory woodlands. Trees within the habitat range from 70 to more than 200 years old. Grazing pastures and residential communities are adjacent to the habitat. Cattle occasionally graze in the forest that comprises the skullcap's habitat.

Distribution

Once, large-flowered skullcap was probably more widespread throughout the southern portion of the Ridge and Valley region of Georgia and Tennessee. In the 1800s, it was collected from Catoosa County, Georgia, and Hamilton County, Tennessee, but it is no longer found in these counties.

There are 17 extant populations12 in Tennessee (in two counties) and five in Georgia (in four counties)varying greatly in size. Three populations (one in Tennessee and two in Georgia) are presumed extirpated due to habitat alterations, including land development and clear-cutting. At the time of listing, there were 10 known populations, with most individuals occurring on only two sites.

Threats

Decades of logging and conversion of land to agricultural uses have taken their toll of old-growth, hardwood forests. As a result, large-flowered skullcap has declined. The few remaining tracts of suitable habitat are widely scattered along ridge tops and in river valleys.

The most significant threats are logging, wild-fires, livestock grazing, farming, herbicide use, and residential development. The two largest populations are on land that is privately owned and highly susceptible to timber harvesting and land change uses. The remainder of the populations are quite small and vulnerable to even slight disturbances in the habitat.

Eight of the 10 known populations are threatened by a low gene pool, causing low seed dispersal and a reduced reproductive capability.

Occasionally, the skullcap has been collected for scientific purpose and horticultural use, and even minimal collection within the small populations gravely threatens the survival potential.

Conservation and Recovery

The most effective conservation measures to date have been protection of habitat. This has been accomplished in large part through land acquisition (Kellys Ferry Slopes, Marshall Forest) and the management of public lands as natural areas (Hicks Gap, Bill McNabb Gulf, Chickamauga Reservoir, Booker T. Washington, and Lookout Mountain). Continued successi.e., the ability to sustain populations of the large-flowered skullcapdepends on the size of the populations, the degree of isolation of the site, and future management practices. Several populations on public land are "islands" surrounded by water and residential development.

Hicks Gap, Tennessee, was designated a Class II State Natural-Scientific Area in 1989, though management activities other than hunting are being delayed until management guidelines for the area are developed in cooperation with the Tennessee Department of Environment and Conservation and te Tennessee River Gorge Trust. In addition to habitat protection, intensive surveys of Marion County, Marshall Forest, and Lookout Mountain sites have been conducted. At all three of these sites, long-term monitoring has been proposed.

In Georgia, plants have been successfully transplanted from a site slated for development and have been relocated to two sites in Chattahoochee National Forest. The plants were collected in 1993 while they were flowering and were held by the Atlanta Botanical Garden over the winter. They were placed on slopes facing east and west, where they have been monitored.

According to the 1996 Recovery Plan for the large-flowered skullcap, long-term monitoring on protected land is an important strategy for the recovery of the species. Monitoring should include permanent plots on areas with different management histories and forest compositions. By following individual plants and plots through several years, trends in recruitment, mortality and reproductive capacity can be determined.

The protection of sizeable populations on private land is another important component of the recovery efforts for the species. Currently, the second and third largest populations occur on private land. These sites support populations considerably larger than several publicly owned and protected sites.

A search for additional populations throughout southeastern Tennessee, northwestern Georgia, and northeastern Alabama will also be conducted to try to increase the number of known extant populations.

The species will be considered for delisting when there are 15 protected and managed self-sustaining populations. Populations must be distributed throughout the range and must be self-sustained for 10 years for the U. S. Fish and Wildlife Service to determine that recovery has advanced enough to remove the species from its Endangered status.

The Recovery Plan recommends intensification of efforts to cultivate the plant. Nursery cultivation will provide a stock for reintroduction into remaining suitable portions of the plant's historic range. The Nature Conservancy is coordinating attempts to acquire further tracts of habitat that would secure large-flowered skullcap's survival.

Contact

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

References

Epling, C. 1942. "The American Species of Scutellaria." University of California Publications in Botany 20(1):1-146.

Kral, R. 1983. "A Report on Some Rare, Threatened, or Endangered Forest-Related Vascular Plants of the South." Technical Publication R8-TP-2. USDA, Forest Service, Washington, D.C.

McCollum, J. L., and D. R. Ettman. 1977. Georgia's Protected Plants. The Georgia Department of Natural Resources, Atlanta.

U.S. Fish and Wildlife Service. 1986. Determination of Endangered Status for Scutellaria montana (Large-flowered Skullcap)." Federal Register 51: 22521-22524.

U.S. Fish and Wildlife Service. 1996. "Recovery Plan for Large-flowered Skullcap." U.S. Fish and Wildlife Service, Atlanta.