Nongame and Rare Species Program: Rare Plant Communities of Texas
Edwards Plateau: Central Texas Mid-grass Prairie
Global Rank: G2G3
Description: Relatively undisturbed openings or grasslands on clay and clay loam soils in the Lampasas Cutplain and eastern Edwards Plateau are typically dominated by Schizachyrium scoparium in a mixture with other grasses, including Sorghastrum nutans, Sporobolus compositus, Bouteloua curtipendula, B. hirsuta, Andropogon gerardii, Nassella leucotricha, Muhlenbergia reverchonii, Bothriochloa laguroides and Aristida purpurea . This community often contains a variety of showy wildflowers of which Melampodium leucanthum, Liatris mucronata, Helianthus maximiliani, Calylophus berlandieri, Oenothera macrocarpa, Salvia spp., and Chamaecrista fasciculata are representative. Other common components are Symphyotrichum ericoides, Hedyotis nigricans, Scutellaria wrightii, Marshallia caespitosa, Thelesperma simplicifolium, Stillingia texana, Polygala alba, Agalinis densiflora, Warnockia scutellarioides, Silphium albiflorum, Desmanthus spp., Mimosa roemeriana, Asclepias viridiflora, A. oenotheroides, and Yucca pallida. Salvia texana and Dalea multiflora tend to be abundant in areas with thinner soils. Woody species such as Juniperus ashei, Prosopis glandulosa,and Rhus lanceolata increase in the absence of fire. Similar grassland communities occur across west-central Texas and into Oklahoma. Principal threats are overgrazing, fire suppression, conversion to other land uses, and invasion by exotic species, especially Bothriochloa ischaemum var. songarica. These communities are widespread but many examples are degraded, with native grasses and forbs poorly represented.