Phlox nivalis ssp. texensis
|pine phlox, Texas trailing phlox|
|Lodd. ssp. texensis Lundell|
|Subshrub, Shrub, Forb/herb|
The following Participating Institutions are custodians for this species in the CPC National Collection:
Mercer Arboretum and Botanic Gardens
The conservation of Phlox nivalis ssp. texensis is fully sponsored.
Dave Berkshire contributed to this Plant Profile.
Once considered extinct, the Texas trailing phlox was rediscovered by Geyata Ajilvsgi of Bryan, Texas in 1972 (Ajilvsgi 1979). This species was eventually federally listed as endangered in 1991 and, since that time, a handful of new populations have been discovered and reintroduction efforts have had some measure of success.
This endangered subshrub with thin needle-like leaves and pink to magenta flowers native the Pineywoods region of southeastern Texas. Flowers may be white (Nemec 2001). Its stems creep along the ground with the final 2 to 15 centimeters growing upright and blooming. Texas trailing phlox flowers mostly from March to May (but nearly year round in cultivation) and resembles the common cultivated creeping garden phlox (Phlox subulata).
P. nivalis ssp. texensis and other members of the Phlox nivalis spp. often grow among pine trees and thus are often referred to as pine phlox. This subspecies (ssp. texensis) differs from other Phlox species by the presence of minute glandular hairs (Wherry 1955). These plants remain evergreen whenever temperatures and moisture levels are favorable (TPW 1997). Early spring and fall rains promote new growth. This species is also well-adapted to fire, and if prescribed burning occurs in April, plants will resprout and flower again in May.
Distribution & Occurrence
The Pineywoods of southeast Texas were originally composed of a long-leaf pine savanna and are the habitat for Phlox nivalis subsp. texensis. In the Pineywoods, Phlox nivalis subsp. texensis inhabits deep, sandy soils under open (Poole 1997) to moderately dense canopies in the transitional regions between pines and stands of mixed pines and hardwoods. Texas Trailing Phlox favors 25-75 percent canopy coverage and declines as the canopy approaches 100%. Understory and shrub canopies are measured at less than 25% and 25-75% herbaceous ground cover in most Phlox sites. Mulch must be thin and not compacted to promote growth. Hardwood and grass mulch compact less than pine needles and must be less than 1 inch in depth (Poole 1997).
Associates include Loblolly and Longleaf pine, Black Hickory, Flameleaf Sumac, Sassafras, Dwarf Paw Paw, St. Andrews Cross, Poison-Ivy , American Beautyberry, Yaupon and Southern Red, Bluejack and Post Oak are now commonly associated with P. nivalis subsp. texensis (USFWS 1991; Poole 1997).
| At time of listing (1991), only one occurrence in Hardin County was known. Since then, populations in Tyler and Polk County have been found. One population has been reintroduced to Big Thicket, and three more sites were found in surveys. Restoration of longleaf-pine habitat on private land has resulted in 2 additional sites. This means a total of 6 new sites have been recorded, not including the current reintroduction (Nemec 2000, 2001).
In 1997, J. Poole reported fewer than 20 populations: 1 population totaling ~ several hundred plants in Hardin County, TX and 1 population of only 6 plants in Tyler County, TX. The largest group of populations exists on Roy E. Larsen Sandyland Sanctuary in Hardin County and is managed by the Texas Nature Conservancy at Sandylands.
Conservation, Ecology & Research
Fire suppression resulting in habitat loss due to canopy closure by encroachment by woody plants (Poole 1997).
Mercer staff and volunteers maintain an expanding population of Phlox nivalis spp. texensis as a permanent educational exhibit within our Endangered Species Garden. These plants often bloom throughout the year and bloom most prolifically during the Spring. Plants self-sow and spread via rhizomes. The Endangered Species Garden, established in 1994 with support from Star Enterprises, displays rare native plants for the public to view year-round. In Spring 2002, the River Oaks Garden Club of Houston (ROGC), TX provided a generous gift to begin the expansion and renovation of Mercers Endangered Species Garden. ROGC also completed the full CPC sponsorship for Phlox nivalis spp. texensis. Mercer and ROGC hope to organize a work day(s) at the Big Thicket reintroduction site this Fall(2002) or Spring of 2003. Mercers veteran native plant volunteer, Carol Kobb, initiated the CPC sponsorship in memory of her friend Millie Gaudino of Conroe, TX.
Mercer Arboretum and Botanic Gardens maintains wild collected seeds for Phlox nivalis spp. texensis dating to 1993. Mercer also banks subsets of rare seeds collected from field surveys and from propagation work with our collaborating CPC institution, the Lady Bird Johnson Wildflower Center, Austin, TX and the National Center for Genetic Resources Preservation (NCGRP) in Ft. Collins, CO (formerly called the National Seed Storage Laboratories). As this species is a listed federally endangered species, maintenance of genetic integrity, documentation of provenance and gene banking is essential.
The 1995 reintroduction project in the Turkey Creek Unit of the Big Thicket Preserve in Hardin County showed a loss of 18 in 1999 from the original 40 set out in in December of 1995 (Wieland 1999). This 1995 reintroduction was a cooperative effort between Mercer Arboretum and Botanic Gardens, Paula Whitefield and Ricky Maxey (now with Texas Parks and Wildlife) of Big Thicket National Preserve and Kathy Nemec of The U.S. Fish and Wildlife Service, Dr. Phillip Malnassey from Lamar University, Dr. Michael Warnock formerly with Sam Houston State Univ., Guy Nesom of the Botanical Research Institute of Texas, Fort Worth Texas, Wendy Ledbetter of the Texas Nature Conservancy, and assisted by volunteers from Garden Clubs of America's Partners in Plants: Garden Club of Houston, The River Oaks Garden Club of Houston and Magnolia Garden Club of Beaumont, TX (Ledbetter 1996). Ike McWhorter, formerly the East Texas Land Steward for the Texas Nature Conservancy at Sandylands Preserve, was the habitat and management specialist for the species at that time.
Texas Trailing Phlox is currently in reintroduction into its historic range, The Big Thicket National Preserve of the National Park Service (NPS). This most-recent reintroduction is funded by a National Parks Service, Department of Interior Grant prepared by Roy Zipp (formerly with Big Thicket National Preserve). This reintroduction is coordinated by Fulton Jean Sonne of The Big Thicket National Preserve. Dr. David Creech of Stephen F. Austin State University, Nacogdoches, TX is propagating the plants for this reintroduction under technical direction by Mercer Arboretum. Mercer Arboretum and Botanic Gardens provided plants in 1995 for the initial reintroduction of this Phlox into the Big Thicket National Preserve.
Continue prescribed burns of habitat.
As this species is a listed federally endangered species, maintenance of genetic integrity, documentation of provenance and gene banking is essential.
Ajilvsgi, G. 1979. Wild flowers of the Big Thicket, East Texas, and Western Louisiana. College Station: Texas A & M University Press. 360p.
Lundell, C.L. 1969. Flora of Texas. Renner, Texas: Texas Research Foundation.
Moseley, C.J. 1992. The official World Wildlife Fund Guide to Endangered Species of North America. Vol. 3. Washington, D.C. Beacham Publishing.
Poole, J.M.; Carr, W.R.; Price, D.M.; Singhurst, J.R. 2007. Rare Plants of Texas. College Station, TX. Texas A&M University Press. 640p.