Physiognomy and Structure: Vegetation consists of open to very open woodlands with stunted canopies of 6- to 15-m tall trees.

Floristics: Fraxinus americana is the characteristic, consistently dominant or codominant canopy species, usually contributing at least 25% cover. Carya glabra and, less frequently, Carya ovata and Carya ovalis are common codominant overstory associates. Quercus montana (= Quercus prinus), Quercus rubra, Juniperus virginiana, Pinus virginiana, and Juglans nigra are minor canopy trees. Understory and shrub layers vary in density, with Ulmus rubra, Celtis occidentalis, Ostrya virginiana, Cercis canadensis, and Rosa carolina the most typical species. The herb layer varies from moderately open to dense and contains a diversity of xerophytic grasses and forbs. Dominant herbs are Muhlenbergia sobolifera, Helianthus divaricatus, Solidago ulmifolia, Carex pensylvanica, Elymus hystrix, and Phacelia dubia. Unusual stands that occur on concave slopes at two Virginia sites have herb layers dominated by Chasmanthium latifolium. Less abundant but relatively constant (50%) herbs include Acalypha virginica, Ambrosia artemisiifolia, Antennaria plantaginifolia, Arabis laevigata, Danthonia spicata, Dichanthelium boscii, Dichanthelium linearifolium, Eupatorium sessilifolium, Geum virginianum, Heuchera americana, Lespedeza frutescens (= Lespedeza intermedia), Polygonum scandens var. cristatum, Pycnanthemum incanum, Saxifraga virginiensis, and Woodsia obtusa. Less frequent but locally abundant or important herbaceous species include Schizachyrium scoparium, Senna marilandica, Symphyotrichum laeve var. concinnum (= Aster laevis var. concinnus), Symphyotrichum oblongifolium, and Tradescantia ohiensis; the last species is prominent at, but confined to, the southernmost sites for this community in Giles and Grayson counties. Solidago juncea, Carex muehlenbergii var. enervis, Lespedeza virginica, and Dichanthelium depauperatum are important species of a variant of this community type occurring on metasedimentary rocks in Maryland, near Harpers Ferry, West Virginia.

An unusual variant of the type, occurring on east- to northeast-facing cliff-like exposures of pyroxene-bearing granites, is somewhat more mesic in character. Fraxinus americana is the sole canopy dominant of this variant, with minor associates of Quercus montana, Tilia americana, Ulmus rubra, and Carya ovata. The shrub layer contains young reproduction of the canopy species, as well as Celtis occidentalis, Ostrya virginiana, Rosa carolina, and Crataegus pruinosa. Scrambling vines of Parthenocissus quinquefolia, Vitis aestivalis, and Toxicodendron radicans are abundant. The herb layer is moderately dense to dense (>60% cover) despite the abundant rock cover. The lithophytes Dryopteris marginalis, Sedum glaucophyllum, Carex communis, and Saxifraga virginiensis contribute the greatest herbaceous cover. Species richness of plot-sampled stands ranges from 46 to 103 taxa per 400 m2 (mean = 66).

Dynamics:  This community is associated with outcrops and thin-soil areas over mafic rocks and, less frequently, granitic, sedimentary, and metasedimentary rocks with high base status. Stands are mostly edaphically maintained but may occasionally be impacted by fires. The exotic herb Commelina communis and the shrub Symphoricarpos orbiculatus, introduced from farther west, are problematic invasives at some sites. Symphoricarpos orbiculatus is particularly aggressive and is capable of covering large areas with dense colonies in a matter of years, once established.