New York Natural Heritage Program
Cork Elm
Ulmus thomasii Sarg.
Dicots

Habitat [-]
In New York, Cork Elm is most often found at dry sites with shallow soils over limestone bedrock, often on ridges or exposed ledges. It may grow with northern hardwood species oak woodlands and forest edges, or in pastures and savannahs (New York Natural Heritage Program 2008). Rocky slopes, limestone outcrops, rich woods, flood plains, stream banks (Flora of North America 1997). Rich upland woods (Gleason and Cronquist 1991). Rich woods and calcareous uplands (Fernald 1970).

Associated Ecological Communities [-]
  • Alvar woodland
    A subset of the limestone woodland community restricted to the alvar region in Jefferson County, New York.
  • Appalachian oak-hickory forest*
    A hardwood forest that occurs on well-drained sites, usually on ridgetops, upper slopes, or south- and west-facing slopes. The soils are usually loams or sandy loams. This is a broadly defined forest community with several regional and edaphic variants. The dominant trees include red oak, white oak, and/or black oak. Mixed with the oaks, usually at lower densities, are pignut, shagbark, and/or sweet pignut hickory.

    * probable association but not confirmed
  • Calcareous pavement barrens
    A savanna community that occurs on nearly level outcrops of calcareous bedrock (limestone or dolomite). The community consists of a mosaic of shrub-savanna, grass-savanna, and rock outcrop vegetation.
  • Calcareous red cedar barrens*
    A small-patch calcareous rocky summit community occurring on dry, south-facing to southwest-facing slopes and low summits. These sites are characterized by stunted, sparse woodlands with small grassland openings.

    * probable association but not confirmed
  • Calcareous talus slope woodland*
    An open or closed canopy community that occurs on talus slopes composed of calcareous bedrock such as limestone or dolomite. The soils are usually moist and loamy; there may be numerous rock outcrops.

    * probable association but not confirmed
  • Limestone woodland
    A woodland that occurs on shallow soils over limestone bedrock in non-alvar settings, and usually includes numerous rock outcrops. There are usually several codominant trees, although one species may become dominant in any one stand.
  • Maple-basswood rich mesic forest*
    A species rich hardwood forest that typically occurs on well-drained, moist soils of circumneutral pH. Rich herbs are predominant in the ground layer and are usually correlated with calcareous bedrock, although bedrock does not have to be exposed. The dominant trees are sugar maple, basswood, and white ash.

    * probable association but not confirmed
  • Northern white cedar rocky summit*
    A community that occurs on cool, dry, rocky ridgetops and summits where the bedrock is calcareous (such as limestone or dolomite), and the soils are more or less calcareous. The vegetation may be sparse or patchy, with numerous rock outcrops. The species have predominantly boreal distributions.

    * probable association but not confirmed
  • Red cedar rocky summit*
    A community that occurs on warm, dry, rocky ridgetops and summits where the bedrock is calcareous (such as limestone or dolomite, but also marble, amphibolite, and calcsilicate rock), and the soils are more or less calcareous. The vegetation may be sparse or patchy, with numerous lichen covered rock outcrops.

    * probable association but not confirmed
  • Successional red cedar woodland*
    A woodland community that commonly occurs on abandoned agricultural fields and pastures, usually at elevations less than 1000 ft (305 m). The dominant tree is eastern red cedar, which may occur widely spaced in young stands and may be rather dense in more mature stands.

    * probable association but not confirmed

Associated Species [-]
  • Sugar Maple (Acer saccharum)
  • Walking-fern Spleenwort (Asplenium rhizophyllum)
  • Maidenhair Spleenwort (Asplenium trichomanes)
  • Back's Sedge (Carex backii)
  • Hitchcock's Sedge (Carex hitchcockiana)
  • Willdenow's Sedge (Carex willdenowii)
  • Bitternut Hickory (Carya cordiformis)
  • Pink Corydalis (Corydalis sempervirens)
  • Beaked Hazelnut (Corylus cornuta ssp. cornuta)
  • Wavy Hair Grass (Deschampsia flexuosa)
  • Marginal Wood Fern (Dryopteris marginalis)
  • White Ash (Fraxinus americana)
  • Herb-robert (Geranium robertianum)
  • (Hepatica acutiloba)
  • Butternut (Juglans cinerea)
  • Red Cedar (Juniperus virginiana)
  • Wood Nettle (Laportea canadensis)
  • Hophornbeam (Ostrya virginiana)
  • Wild Blue Phlox (Phlox divaricata)
  • Eastern White Pine (Pinus strobus)
  • Burr Oak (Quercus macrocarpa)
  • Chinkapin Oak (Quercus muhlenbergii)
  • Littleleaf Buttercup (Ranunculus abortivus)
  • Bluestem Goldenrod (Solidago caesia)
  • American Bladdernut (Staphylea trifolia)
  • White Basswood (Tilia americana)
  • Eastern Poison Ivy (Toxicodendron radicans)
  • Eastern Hemlock (Tsuga canadensis)
  • American Elm (Ulmus americana)
  • Northern Prickly-ash (Zanthoxylum americanum)