Texas Trailing Phlox
Texas Trailing Phlox
Phlox nivalis ssp. texensis
|Listed||September 30, 1991|
|Description||Trailing, hairy, evergreen perennial, bearing clusters of purple, pink, or white flowers.|
|Habitat||Sandy soil in longleaf pine savannah.|
|Threats||Low numbers; residential and silvacultural development.|
Phlox nivalis ssp. texensis (Texas trailing phlox) is a clump-forming perennial with spreading, evergreen, hairy shoots that grow to a height of 12 in (30 cm). Sterile shoots have needle-like leaves, while fertile shoots have short, lanceolate leaves. The purple-lavender, deep pink, rose, or white flowers occur in clusters of three to six in late March and early April. The fruit capsule has three chambers, each containing a single seed.
The species is endemic to the Big Thicket Forest in eastern Texas, north and west of Beaumont. It has been found in open, grassy longleaf pine (Pinus paulstra ) savannah in sandy soil. It often grows in association with Bothriochloa spp., hickory (Carya spp.), and yaupon (Ilex vomitoria).
Texas trailing phlox was first collected in 1931 in Hardin County, Texas. It has been found in Hardin, Tyler, and Polk counties. In the 1940s it was collected from seven localities in Tyler County, and was considered abundant in the pinelands between Woodville and Warren. In 1980 the species was found at only five sites: three in Tyler County, and two in Hardin County.
The most current survey (1989) documented only two surviving populations. The largest is in Hardin County on land owned by the Nature Conservancy (TNC), where a few hundred plants occur in sandy soil in a former pine plantation. The Tyler County population consists of only six clumps of plants at the edge of a pine plantation.
Texas trailing phlox has shown a significant decline over recent decades, primarily because of land clearing for housing construction and the establishment of pine plantations. A population on land adjacent to TNC land was destroyed by construction of a pipeline.
Conservation and Recovery
Active management is necessary to keep suitable habitat of the Texas trailing phlox from changing through natural succession. TNC is conducting a program of prescribed burning and slash pine removal to maintain the critical habitat on its lands. Other habitats are on private land and along highway rights-of-way, and are potentially threatened by development, road maintenance, and other activities. These critical habitats should also be protected. This could be done by acquiring the habitats and establishing ecological reserves, by negotiating conservation easements with the landowners, or by ensuring appropriate management on the rights-of-way. The Fish and Wildlife Service published a Recovery Plan for the Texas trailing phlox in 1995. The goal of the Recovery Plan is to achieve at least 12 protected and managed, self-maintaining populations of the rare plant. This will be achieved by protecting and managing known populations, searching for additional ones, and by establishing new ones on suitable habitat. The plan also has provisions for monitoring populations of the Texas trailing phlox and studying its ecology and habitat needs.
Mahler, W. F. 1980. "Status Report, Phlox nivaIis ssp. texensis. Lindell." U.S. Fish and Wildlife Service, Albuquerque.
U.S. Fish and Wildlife Service. 1995. "Texas Trailing Phlox Recovery Plan." U.S. Fish and Wildlife Service, Albuquerque, New Mexico.
Wherry, E. T. 1966. "Polemoniaceae." In Flora of Texas, edited by C. L. Lundell. 1(3): 283-321.