Edwards Plateau Carbonate Glades and Barrens (Not Mapped)
Geology
Non-slope forming members of the Glen Rose formation, or areas of massive limestones such as Edwards Limestone.
Landform
Usually level to gently sloping uplands on plateau tops, or level benches between slopes in stair step topography.
Soils
Very shallow soils, sometimes very little soil development over rocky substrates.
Parent Description
These are generally small patch occurrences with very sparse herbaceous cover, sometimes with occasional scattered shrubs. These sites generally co-occur with savannas, representing the shallowest soils sites, often on exposed or near-exposed limestone. They may occur as bands with adjacent grasslands, shrublands, or open woodlands. Herbaceous cover may include species such as Chaetopappa bellidifolia (hairy leastdaisy), Evax prolifera (rabbit's tobacco), Croton monanthogynus (prairie-tea), Sedum nuttallianum (yellow stonecrop), Sedum pulchellum (widowscross), Sporobolus vaginiflorus (poverty dropseed), Centaurium texense (Texas centaury), Spermolepis inermis (spreading scaleseed), Chamaesyce serpens (matted sandmat), Heliotropium tenellum (pasture heliotrope), Lesquerella spp. (bladderpod), and others.
A possible outlier (the system occurring well outside the ecoregion within which it is normally found) of this system consists of small patch occurrences of very sparse herbaceous cover found on very shallow soils over chalk outcrops in isolated locales of North Texas (Gober, Annona, Austin Chalk and Pecan Gap formation). Species include Bouteloua rigidiseta (Texas grama), Sedum pulchellum (Texas sedum), Sporobolus vaginiflorus (poverty dropseed), Nostoc commune (nostoc), Penstemon cobaea (white beardtongue), and Lesquerella spp. (bladderpod). Adjacent woodlands or savannas on thin-soiled chalk ridges may contain Quercus shumardii (Shumard oak), Quercus muehlenbergii (chinkapin oak), Celtis spp. (hackberry), Cornus drummondii (roughleaf dogweed), Viburnum rufidulum (rusty blackhaw), Fraxinus texensis (Texas ash), and others.