U.S. FISH AND WILDLIFE SERVICE
DIVISION OF ENDANGERED SPECIES

SPECIES ACCOUNTS

FAMILY: Xyridaceae

STATUS: Endangered, Federal Register, July 26, 1991

DESCRIPTION: This member of the yellow-eyed grass family is a perennial which ranges from 7 to 1O decimeters (2.3 to 3.3 feet) in height. Plants typically occur in clumps where they arise from fleshy bulbous bases. Leaves are basal, the outermost scale-like, the larger ones linear, twisted, deep green and 14 to 45 centimeters (cm) (5.5 to 17.7 inches) long. The inflorescence consists of brown conelike spikes, 1 to 1.5 cm (O.4 to O.6 inch) in length, which occur singly at the tips of long slender stalks from 3O to 7O cm (1 to 2 feet) long. The flowers, which are pale yellow in color and 4.5 millimeters (mm) (O.2 inch) long, unfold in the late morning and wither by mid-afternoon. Fruits are thin-walled capsules containing numerous seeds O.5 to O.6 mm (O.O2 inch) in length. Flowering occurs from August through September (Kral 1978, 1983, 199O).

RANGE AND POPULATION LEVEL: Currently, only seven populations are known to be extant, consisting of five sites in Lewis County, Tennessee, and one site each in Bartow County, Georgia, and Franklin County, Alabama. These isolated remnants are located over three different physiographic provinces: the Cumberland Plateau of Alabama; the Western Highland Rim of Tennessee; and the Valley and Ridge Province of Georgia (Kral 199O). Population size ranges from a few dozen plants at one site to thousands of individuals at two sites. Most sites support populations of a few hundred plants and each site occupies less than an acre in area. An historical record exists for Gordon County, Georgia.

HABITAT: Xyris tennesseensis occurs in seep-slopes, springy meadows, or on the banks or gravelly shallows of small streams. As with all Xyris, the habitat is open or thinly wooded and the soils are moist to wet year-round. However, this species differs from other Xyris in being found in areas where calcareous rocks are at or near the soil surface. Thus, its soils are circumneutral to basic instead of acidic. Common associates include ferns and fern allies such as Osmunda; Thelypteris palustris; and Lycopodium appressum (clubmoss); grasses such as Leersia oryzoides (cut grass); Panicum (panic grass); and Andropogon (beard grass); and sedges such as Scirpus atrovirens (bulrush); Eleocharis (spikerush); Cyperus (flat-sedge); Rhynchospora caduca (beak-rush); and R. capitellata. Juncus is common with J. brachycephalus being a constant associate. Dominant dicots are Phlox glaberrima; Lysimachia lanceolata (loosestrife); Solidago patula (golden-rod); Rudbeckia fulgida umbrosa; Eupatorium perfoliatum (Thoroughwort); and Parnassia grandiflora (grass of parnussus) in Tennessee. Woody vegetation on the border of seeps or along streambanks include Alnus (alder); Salix (willow); Sambucus elderberry; Cornus canadensis (dogwood); and Cephalanthus occidentalis (button bush). The surrounding forests consist of upland species common to the oak-hickory, oak-pine or oak-juniper type (Kral 1983, 199O).

REASONS FOR CURRENT STATUS: This species' habitat has been impacted or lost due to its conversion to row crop agricultural or pastureland. A population in Gordon County, Georgia was destroyed when the site was converted to a soybean field. Other sites have been adversely affected by timber operations. Timbering upslope leads to increased erosion, deposition into the seeps, and water quality degradation of the watershed (Kral 199O). Habitat for the Alabama population has been disturbed by timbering and gravel quarrying (for use in the adjacent highway). Since 1982, the number of plants at this site have significantly declined (from hundreds to less than 1OO due to disturbances and the use of herbicides in right-of-way maintenance. Highway construction caused the destruction of a second population in Georgia (Bartow County). Three other populations are located near roads and are potentially threatened by road improvement measures. Xyris tennesseensis occurs in habitat which is "open" and is vulnerable to overcrowding and shade associated with woody plant encroachment. Furthermore, open wet areas are essential for successful germination (Kral 1988). In Lewis County, Tennessee, one population has been lost and a second is declining from the increased competition with succession (Kral 1990). While succession is a slow and natural process, it poses a threat to this species due to the small number of populations and limited amount of suitable habitat remaining (U.S. Fish and Wildlife Service 1991). This species is vulnerable to diversion of seep or ground water. Kral (1990) noted that water tables are dropping throughout the area, resulting in the loss of many of the seeps and springheads.

MANAGEMENT AND PROTECTION: Most populations are located on private land; however, plants extend onto a State maintained highway right-of-way in Alabama and onto National Park Service land (NPS) in Lewis County, Tennessee. The Tennessee Department of Conservation (TDC) and Tennessee Nature Conservancy have several voluntary protection agreements with private landowners. The NPS manages and protects the population on their property through an agreement with the TDC. The Alabama Highway Department is aware of the population near the highway in Alabama and the importance of protecting the site. The Service will continue to work with involved agencies and landowners to develop protection and management plans for all sites. Studies are needed to determine if management is necessary to ensure a continuum of available habitat due to the loss of populations through succession.

REFERENCES:

Kral, R. 1978. A new species of Xyris (sect. Xyris) from Tennessee and northwestern Georgia. Rhodora 80 (823):444-447.

Kral, R. 1983. Xyris tennesseensis. In: A report on some rare, threatened, or endangered forest-related vascular plants of the South, Vol. 1:166-169. USDA Forest Service, Technical Publication R8-TP 2.

Kral, R. 1988. A preliminary report on Xyris tennesseensis. Unpublished report submitted to U.S. Fish and Wildlife Service, Jackson, Mississippi. 6 pp.

Kral, R. 1990. A status report on Xyris tennesseensis. Unpublished report submitted to U.S. Fish and Wildlife Service, Jackson, Mississippi. 22 pp.

U.S. Fish and Wildlife Service. 1991. Endangered and threatened wildlife and plants; determination of endangered status for Xyris tennesseensis (Tennessee yellow-eyed grass). Federal Register 56(144):34151-34154.

For more information please contact:

U.S. Fish and Wildlife Service
6578 Dogwood View Parkway Suite A
Jackson, Mississippi 39213

Telephone: 601/965-4900