Name:
Saxifraga michauxii Herbaceous Alliance
Reference:
Southeastern Ecology Working Gro...
Description:
This alliance consists of moderate- to high-elevation rocky summit communities of the southern and central Blue Ridge (metamorphic rock portions of the southern and central Appalachians), on various rock types, including amphibolite, metabasalt (greenstone), gneiss, and others. There are several globally rare communities contained in this alliance. More common vegetation in this alliance will have Saxifraga michauxii as a characteristic component; other species are variable, but may include Saxifraga virginiensis, Saxifraga micranthidifolia, Carex spp., Schizachyrium scoparium, and others. Examples at high elevation exhibit a sparse vegetative cover of grasses, forbs and shrubs rooted in rock fissures and occur in a matrix of Picea rubens - Abies fraseri Forest. On rock outcrops of highly fractured felsic to mafic bedrock (over 1980 m), typical species include Carex misera, Abies fraseri, Menziesia pilosa, Heuchera villosa, Rhododendron catawbiense, Saxifraga michauxii, Sorbus americana, Oclemena acuminata (= Aster acuminatus), Solidago glomerata. Other characteristic species are Minuartia groenlandica and Polypodium appalachianum. On rock outcrops of felsic Anakeesta slate in the Great Smoky Mountains (from 1646-1987 m), typical species include Saxifraga michauxii, Carex misera, Calamagrostis cainii, Rhododendron carolinianum, Solidago glomerata, Oclemena acuminata, Abies fraseri, and Leiophyllum buxifolium. Other characteristic species are Gentiana linearis and Calamagrostis cainii. At low to middle elevations (1256-1713 m) in the southern Appalachians on outcrops of mafic rock, or on felsic rock where perennial seepage exists, the sparse vegetation consists of graminoids, forbs, and shrubs. It is surrounded by deciduous forests dominated by Quercus rubra, Acer rubrum var. rubrum, and occasionally Tsuga caroliniana. Typical species here include Saxifraga michauxii, Coreopsis major, Schizachyrium scoparium, Kalmia latifolia, Dichanthelium acuminatum, Danthonia spicata, and Paronychia argyrocoma. Other characteristic species include Campanula divaricata, Solidago bicolor, and Allium cernuum (= Allium allegheniense). On amphibolite, metabasalt, metagabbro, or metagraywacke bedrock from 1350-1870 m elevation within a matrix of Quercus rubra Forest or high elevation grasslands and shrublands, the vegetation includes Saxifraga michauxii, Danthonia spicata, Krigia montana, Carex misera, Angelica triquinata, Athyrium filix-femina ssp. asplenioides, Rhododendron catawbiense, and Heuchera villosa. Other characteristic species are Sanguisorba canadensis, Sibbaldiopsis tridentata, Hylotelephium telephioides (= Sedum telephioides), Houstonia purpurea var. montana, Geum radiatum, Solidago spithamaea, and Huperzia appalachiana. In the central Blue Ridge mountains of Virginia, at elevations of 850-1200 m, this alliance occurs on greenstone (metabasalt, a mafic metamorphic rock). Characteristic herbaceous species include Hylotelephium telephioides, Solidago simplex var. randii, Heuchera pubescens, Deschampsia flexuosa, Houstonia longifolia (= Houstonia longifolia var. compacta), Dennstaedtia punctilobula, Campanula divaricata, Agrostis perennans, Carex pensylvanica, Saxifraga michauxii, Arabis lyrata, Allium allegheniense?, Phlox subulata ssp. brittonii, Sibbaldiopsis tridentata, Liatris turgida, Huperzia appalachiana, Polypodium appalachianum, Gymnocarpium appalachianum, and Oclemena acuminata. Shrubs include Physocarpus opulifolius, Sorbus americana, Betula alleghaniensis, Quercus rubra, Ribes rotundifolium, Diervilla lonicera, Hamamelis virginiana, Ilex montana, Kalmia latifolia, Menziesia pilosa, and Abies balsamea. Rare alpine disjunct species are sometimes present, including Juncus trifidus and Trisetum spicatum.
Accession Code:
VB.CC.18407.SAXIFRAGAMICHAU
Plot-observations of this Community Concept:
0
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