Curtis (1959) described the eastern red-cedar thicket (cedar glade) community as a type of savanna. Most cedar glades occur on steep, dry sandstone, quartzite, rhyolite, or dolomite bluffs. The dominant tree is eastern red cedar (Juniperus virginiana), which may occur as scattered trees or shrubs, or, in thickets, interspersed with prairie-like openings. Red maple (Acer rubrum), paper birch (Betula papyrifera) and black and bur oaks (Quercus velutina and Q. macrocarpa) may also be present. Apart from rocky bluffs, cedar glade may also occur on very dry, gravelly slopes on south- or west-facing morainal ridges, or on coarse-textured sandy terraces along major rivers in western Wisconsin.
Today's dense "cedar thickets" are usually, if not always, the result of fire suppression on dry prairies. Prior to European settlement cedar glades may have occurred only where extensive cliffs, rivers, or lakes served as firebreaks. Common herbs include native bluestem and grama grasses (Andropogon spp. and Bouteloua spp.), prickly-pear cactus (Opuntia macrorhiza), flowering spurge (Euphorbia corollata), stiff sandwort (Minuartia michauxii), and gray goldenrod (Solidago nemoralis). The associated flora strongly resembles those of the dry prairie and sand prairie communities, with elements of dry cliff, oak barrens, and oak openings also present.
