Texas Coast Dune and Coastal Grassland

Geology

Eolian deep sands and Pleistocene barrier island and beach deposits of the Beaumont formation. This includes deep sands well inland on the South Texas Sand Sheet.

Landform

Primary and secondary dunes, as well as relatively level areas, on the mainland where deep sands are deposited. Significant local topography, in the form of swales and pothole wetlands, may be present but are excluded from this system. But, significant surface drainages are generally scarce.

Soils

Deep or coastal sands.

Parent Description

This system includes upland, grass-dominated vegetation on deep sands. Dunes are often dominated by Uniola paniculata (sea oats), with other species such as Croton punctatus (Gulf croton), Panicum amarum (bitter panicum), Ipomoea pes-caprae (goat-foot morning-glory), Ipomoea imperati (beach morning-glory), Tidestromia lanuginosa (wooly tidestromia), Cakile spp. (searocket), and Sesuvium portulacastrum (shoreline seapurslane) also present. Upland grasslands are often dominated by Schizachyrium littorale (seacoast bluestem) and Paspalum monostachyum (gulfdune paspalum). Numerous other species, such as Sorghastrum nutans (Indiangrass), Paspalum plicatulum (brownseed paspalum), Muhlenbergia capillaris (Gulf muhly), Cenchrus spinifex (common sandbur), Elionurus tripsacoides (Pan American balsamscale), Eragrostis secundiflora (red lovegrass), Bothriochloa laguroides ssp. torreyana (silver bluestem), Heteropogon contortus (tanglehead), Andropogon glomeratus (bushy bluestem), Spartina patens (marshhay cordgrass), and Dichanthelium spp. (rosette grasses) may also be common. Numerous forbs, including such species as Heterotheca subaxillaris (camphor weed), Croton spp. (crotons), Chamaecrista fasciculata (partridge pea), Rayjacksonia phyllocephala (camphor daisy), Physalis spp. (groundcherries), Helianthus argophyllus (silverleaf sunflower), Gaillardia pulchella (Indian blanket), Solidago sempervirens (seaside goldenrod), Baptisia spp. (wild-indigos), Indigofera miniata (scarlet-pea), Eriogonum multiflorum (heartsepal wildbuckwheat), Conoclinium betonicifolium (betonyleaf thoroughwort), and Rudbeckia hirta (blackeyed Susan) are also commonly encountered. Some woody species are found in the system, but typically make up very little cover. Cover of woody species is limited, but may include Baccharis spp. (baccharis), Opuntia engelmannii var. lindheimeri (Lindheimer pricklypear), Morella cerifera (wax-myrtle), Quercus fusiformis (plateau live oak), Quercus virginiana (coastal live oak), and stunted Prosopis glandulosa (honey mesquite). Non-native woody species such as Tamarix spp. (salt cedars), Schinus terebinthifolius (Brazilian peppertree), and Triadica sebifera (Chinese tallow) may be present to dominant. Small areas may have sufficient woody cover to be mapped as a shrubland.