Texas Trailing Phlox (Phlox nivalis subsp. texensis)
- Other Names
- Texan Phlox
- Texas Status
- U.S. Status
- Endangered, Listed 9/30/1991
- Texas trailing phlox is an evergreen perennial herb or shrub. Plants often form clumps, but not mats. The stems tend to spread along the ground, with only the upper one to six inches of the stem erect. Leaves are about 5/8 inch long, needle-like, and densely packed on the stem. Young stems produce the flowers, are more or less erect, and have leaves that are longer and lighter-green in color. Older stems have smaller leaves, darker-green in color, and typically lie directly on the surface of the ground. The flowers are pink to magenta in color. Flowers have five petals, each about 3/8 inch in length.
- Life History
- Flowering occurs during March through May. Texas trailing phlox plants are evergreen, growing whenever temperature and moisture conditions are favorable. New growth is most often seen during periods of highest rainfall, in early spring and early fall. Little is known about the pollination of this species; however, based on the plant s floral structures, butterflies are the most likely pollinators. Individual plants may produce 3 to 50 or more flowers, depending on the size of the plant. A plant may bloom over a period of one to 5 weeks.
Texas trailing phlox is well-adapted to fire. Although aboveground parts of the plant are destroyed by fire, underground parts are undamaged, and new growth appears within two weeks after a spring burn. If prescribed burning occurs in April, even plants that had flowered before the fire will resprout and flower again in May. Other plant species which grow in association with Texas trailing phlox include longleaf pine, loblolly pine, black hickory, southern red oak, bluejack oak, post oak, flameleaf sumac, yaupon, sassafras, dwarf pawpaw, St. Andrews cross, poison-oak, and American beautyberry.
The main factor in the decline of Texas trailing phlox has been the loss of open, fire-maintained forests, especially longleaf pine. Habitat loss and degradation due to site preparation for pine plantations, land clearing for pasture establishment, exposure to herbicides, and activities associated with development have also contributed to the decline of this species. Recent increases in the number of plants at some study sites indicate that periodic fire is essential to maintain the open pine woodland essential to the survival of this species.
- Texas trailing phlox grows on sandy soils in fire-maintained open pine woodlands.
- Texas trailing phlox occurs in fewer than 20 populations in Hardin, Polk, and Tyler counties.
- The U.S. Fish and Wildlife Service listed Texas trailing phlox as endangered in September 1991.