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A2072 Hydrangea arborescens / Heuchera villosa Appalachian Circumneutral Cliff Alliance

Type Concept Sentence: These are moist shaded cliffs, usually with some seasonal seepage that occur in the Appalachian region on a variety of substrates, from siltstones and shales, to limestones, including some calcareous sandstones. Herbaceous species are variable among associations and even patchily within a stand. Most typical vascular species are Heuchera villosa var. villosa, Asplenium trichomanes ssp. trichomanes, and Thalictrum clavatum.

Common (Translated Scientific) Name: Wild Hydrangea / Hairy Alumroot Appalachian Circumneutral Cliff Alliance

Colloquial Name: Southern & Central Appalachian Circumneutral Cliff

Hierarchy Level:  Alliance

Type Concept: These are moist shaded cliffs, usually with some seasonal seepage that occur in the Appalachian region on a variety of substrates, from siltstones and shales, to limestones, including some calcareous sandstones. Herbaceous species are variable among associations and even patchily within a stand. Most typical vascular species are Heuchera villosa var. villosa, Asplenium trichomanes ssp. trichomanes, and Thalictrum clavatum. Other vascular species present include Asplenium montanum, Dryopteris intermedia, Dryopteris marginalis, Hydrangea arborescens, Laportea canadensis, Polypodium appalachianum, Rhododendron maximum, Trautvetteria caroliniensis var. caroliniensis, and (rarely) Eurybia divaricata, Phegopteris connectilis, and Saxifraga caroliniana. Conocephalum conicum is a common and conspicuous nonvascular plant.

Diagnostic Characteristics: Circumneutral cliffs of the Central and Southern Appalachian regions.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance is widely variable floristically and is based on environmental setting and the presence of the two nominal species.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This alliance contains vegetated, dry to moist, basic cliffs of variable geology, with vegetation composition variable and often with a mixed and variable physiognomy. Individual occurrences may be herb-dominated, shrub-dominated, or sparsely vegetated with vascular plants (though sometimes with dense patchy cover of mosses, hepatics, or lichens).

Floristics: Hydrangea arborescens is a characteristic and sometimes abundant shrub; Rhododendron minus, Cercis canadensis, and Clethra acuminata may also occur. Saplings and stunted trees, including Acer saccharum, Acer nigrum, Carpinus caroliniana, Fraxinus americana, Juniperus virginiana var. virginiana, Ostrya virginiana, Quercus rubra, Quercus montana (= Quercus prinus), Tilia americana, Tsuga canadensis, Ulmus rubra, and Ulmus americana, may occur on the cliff-faces. Toxicodendron radicans and Parthenocissus quinquefolia are common vines. The herb layer is characterized by Heuchera villosa var. villosa; other herbaceous species vary widely and may include Ageratina altissima, Aquilegia canadensis, Arabis laevigata var. laevigata, Asplenium montanum, Asplenium trichomanes ssp. trichomanes, Campanula divaricata, Carex communis, Carex platyphylla, Danthonia spicata, Dichanthelium depauperatum, Dichanthelium dichotomum, Dicentra eximia, Heuchera americana, Laportea canadensis, Dryopteris intermedia, Dryopteris marginalis, Eurybia divaricata (= Aster divaricatus), Oxalis violacea, Parietaria pensylvanica, Philadelphus hirsutus, Philadelphus inodorus, Pilea pumila, Polymnia canadensis, Polypodium appalachianum, Polystichum acrostichoides, Saxifraga virginiensis, Sedum ternatum, Solidago caesia, Symphyotrichum cordifolium (= Aster cordifolius), Thalictrum clavatum, Trautvetteria caroliniensis var. caroliniensis, Woodsia obtusa, and Viola triloba (= Viola x palmata var. triloba).

Dynamics:  No Data Available
Environmental Description:  This alliance is known from vertical and near-vertical exposures of limestone, siltstone, mudstone, calcareous sandstones, and may also occur on mafic metamorphic and igneous rocks.
Geographic Range: This alliance ranges from the Potomac drainage in Maryland to the Southern Blue Ridge, Ridge and Valley, Cumberlands, and Interior Low Plateau.

Nations: US

States/Provinces:  AL, GA?, MD, NC, TN, VA, WV?


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 6 Open Rock Vegetation Class C06 6
Subclass 6.B Temperate & Boreal Open Rock Vegetation Subclass S04 6.B
Formation 6.B.1 Temperate & Boreal Cliff, Scree & Other Rock Vegetation Formation F034 6.B.1
Division 6.B.1.Na Eastern North American Temperate Cliff, Scree & Rock Vegetation Division D051 6.B.1.Na
Macrogroup 6.B.1.Na.1 Shrubby Fivefingers - Rock Polypody / Cup Lichen species Eastern North American Cliff & Rock Vegetation Macrogroup M111 6.B.1.Na.1
Group 6.B.1.Na.1.c Appalachian Cliff & Rock Vegetation Group G840 6.B.1.Na.1.c
Alliance A2072 Wild Hydrangea / Hairy Alumroot Appalachian Circumneutral Cliff Alliance A2072 6.B.1.Na.1.c
Association CEGL004395 (Wild Hydrangea, Eastern Poison-ivy) / American Alumroot - (Starved Witchgrass, Common Cliff Fern) Cliff Shrubland CEGL004395 6.B.1.Na.1.c
Association CEGL006479 Wild Hydrangea / Woodland Stonecrop - Rock Polypody Cliff Shrubland CEGL006479 6.B.1.Na.1.c
Association CEGL008435 (Wild Hydrangea) / Hairy Alumroot - Maidenhair Spleenwort - Mountain Meadowrue / Snakeskin Liverwort Cliff Shrubland CEGL008435 6.B.1.Na.1.c
Association CEGL008546 (Wild Hydrangea) / Hairy Alumroot - Appalachian Bleeding-heart - Small Bonny Bellflower Cliff Shrubland CEGL008546 6.B.1.Na.1.c
Concept Lineage: A.1905 in part

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: No Data Available
Concept Author(s): M. Pyne, in Faber-Langendoen et al. (2013)

Author of Description: M. Pyne and L.A. Sneddon

Acknowledgements: No Data Available

Version Date: 12-18-14
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Schafale, M. P., and A. S. Weakley. 1990. Classification of the natural communities of North Carolina. Third approximation. North Carolina Department of Environment, Health, and Natural Resources, Division of Parks and Recreation, Natural Heritage Program, Raleigh. 325 pp.