The following Participating Institutions are custodians for this species in the CPC National Collection:
Mercer Arboretum and Botanic Gardens
The conservation of Abronia macrocarpa is fully sponsored.
Dave Berkshire contributed to this Plant Profile.
The large-fruited sand verbena is a graceful perennial member of the four o'clock family and is native to sandy areas of East Texas. The stems are ascending to erect, to 50 cm tall. The sand verbena produces among the region's most attractive inflorescences. In spring, head-like clusters of 20-75 fuchsia to magenta flowers 18-30 mm long are borne above light green, hairy, sticky leaves. Intensely scented flowers open at dusk and attract moths throughout the evening hours until dawn. Plants are self-infertile with viable fruit occurring only as result of plant-to-plant crosses (Williamson and Bazeer 1997). The fruits 8-15 mm long, heart-shaped in side view and have 5 papery wings. Wind-blown fruits travel across the plant's habitat thus dispersing the fruit's seeds. After flowering the plant goes dormant for the summer, surviving as a taproot.
Abronia macrocarpa is adapted to the harsh and fragile sandy openings and dunes in savannah-like woodlands. These regions are characterized by deep, sandy infertile soils, disturbed areas with low and unreliable precipitation levels and extreme daily and yearly temperature fluctuations. First collected in 1968 but not formally described until 1972, the plant has been federally listed as endangered since 1988 (Reed 2001; Tiller 2001; Williamson 2001).
Distribution & Occurrence
A. macrocarpa is found on sandy substrates, including blowouts, aeolian sand deposits, and sandy dunes in post oak and grassland mosaic vegetation types. Soil type of one site in Freestone County, which contains thousands of individuals, is characterized as the Pickton loamy fine sands in the southern portion and Wolfpen loamy fine sand at the northern extent (Williamson 2001).
|9 sites with a total of many 1000 plants (Texas State University - San Marcos)
Report from 2006 for 9 populations:
Population 1 Freestone County, TX ~28K on 20 acres
Population 2 Leon County, TX ~6,200 on 5.5 acres
Population 3 Leon County, TX ~12K on over 90 acres
Population 4 Leon County, TX ~8K on 8.5 acres
Population 5 Robertson County, TX ~5K on 2.7 acres
Population 6 Robertson County, TX 750 on 10.6 acres
Population 7 Robertson County, TX 4,500 on12 acres
Population 8 Leon County, TX ~30K on 30 acres
Population 9 Leon County, TX area and number not determined (discovered in 2006)
Therefore, a total nearly 100,000 plants in all size classes have been observed by Dr. Paula Williamson of Texas State University at San Marcos, TX and Gena K. Janssen of Janssen Biological of Austin, TX for 6 of the populations.
AbroniaBees: Bumble bees1(Bombus1), Miner bees1( Anthohpora1)
Moths: Sphinx moth1
Abronia ammophilaBees: Bumble bees (Bombus fernaldae2, Bombus mixtus2, Bombus sylvicola2)
Butterflies: Silvery blue (Glaucopsyche lygdamus2),Tortoiseshell butterfly2 (Aglais milberti2), Comma butterfly2(Polygonia faunus2), Western white2 (Pontia occidentalis2)
Moths:Noctuid moths2 (Autographa pseudogamma2, Copablepharon viridispara2, Hada sutrina2, Papestra quadrata2), Sphinx moths2 (Hyles lineata2)
Conservation, Ecology & Research
Abronia macrocarpa is self-incompatible (Williamson et al. 1997).
Germination protocols continue to be standardized by staff at Mercer Arboretum.
In January of 2002 Mercer Arboretum and Botanic Gardens received seed collected during the 2001 growing season from the six wild populations studied by Dr. Paula Williamson in 2001. Subsets of these seeds were banked at Mercer Arboretum and Botanic Gardens, 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). Mercer maintains wild collected seeds for this species dating to 1989. Both Williamson and Janssen maintain strong partnerships with private landowners where Abronia macrocarpa grows.
Dr. Williamson presented the 2002 field growing season reports and current research in her seminar Status of the Large-fruited Sand Verbena (Abronia macrocarpa) on Sept. 5, 2002 at the TX Plant Conservation Conference 2002 at the Lady Bird Johnson Wildflower Center in Austin, TX.
Plants produced for educational display gardens or for specific restoration and reintroduction projects are produced within Mercers nursery greenhouses and within our Conservation Area. The Conservation Area provides secure, raised beds for mass propagation of plants/seeds. Each bed is provided with independently controlled irrigation and substrates that meet the unique requirements for each species.
Mercer has maintained an experimental population of Abronia macrocarpa for ~9 years at our Conservation area. Seeds gathered from these plants are used for educational garden displays and propagation experiments. In November 2001, several young plants were transplanted from the Conservation area to Mercers Endangered Species Garden. These Abronia macrocarpa transplants provided a beautiful display of blooms for the public during the Spring of 2002 and should provide a permanent exhibit for years to come. 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, TX provided a generous gift to be used for the initiation of the expansion and renovation of Mercers Endangered Species Garden. (Tiller 2001b)
Studies of demographic and genetic viability are needed. Continue habitat characterization.
Expand reserve seed bank and cultivated populations.
Cheatum, S.; Johnston, M.C.; Marshall, L. 1995. The useful wild plants of Texas, the southeastern & southwestrn United States, the southern olains and northern Mexico. Vol. 2, Abronia-Arundo. Austin, Texas. Useful Wild Plants.
Lowe, D.W.; Matthews, J.R.; Moseley, C.J. 1990. The Official World Wildlife Fund guide to endangered species of North America. Vol. 1. Washington, D.C. Beachham Publishing.
Ogorzaly, M.D. 1986. Color illustrations of rare plants. In Natural Heritage of Texas map, compiled by General Land Office & Texas Natural Heritage Program. Austin, Texas. Continental Map.
Poole, J.M.; Carr, W.R.; Price, D.M.; Singhurst, J.R. 2007. Rare Plants of Texas. College Station. Texas A&M University Press. 640p.
Poole, J.M.; Riskind, D.H. 1987. Endangered, threatened, or protected native plants of Texas. Austin, TX: Texas Parks Wildlife Department.