Southeastern Naturalist
W.N. Grafton and R.H. Fortney
2015 Vol. 14, Special Issue 7
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Canaan Valley & Environs
2015 Southeastern Naturalist 14(Special Issue 7):210–217
Exotic and Invasive Plants in Canaan Valley
William N. Grafton1, 3 and Ronald H. Fortney2, 3
Abstract - The rare plants and unusual wetland communities of Canaan Valley are potentially
threatened by establishment of exotic and invasive plants. We consulted various
references and assembled a list of 106 invasive and/or exotic plant species that have
been found growing in Canaan Valley; the most speciose families are Poaceae (grasses),
Fabaceae (legumes), and Asteraceae (sunflowers). We recommend that diverse local
stakeholders cooperate to plan and implement a program to prevent the establishment of
highly invasive plants in Canaan Valley.
Introduction
Canaan Valley (hereafter, the Valley), in Tucker County of northeastern West
Virginia, is a high-elevation oval basin. Oriented northeast–southwest, the Valley’s
floor is 13.0 miles (21.7 km) long, averages 2.4 miles (4.0 km) wide, and is
about 3298 feet (999 m) above sea level. On the Valley’s eastern side, the highest
points of Cabin Mountain range from 3904 to 4402 feet (1183–1334 m) above sea
level; to the west, the ridge that includes Canaan and Brown Mountains reaches
3462 to 3875 feet (1049–1174 m). The high point on the Valley’s northern side is
3656 feet (1108 m) in elevation.
Until it was timbered during 1907–1924, the Valley’s floor supported an
excellent example of a virgin Picea rubens Sarg. (Red Spruce) forest (Allard
and Leonard 1952). In contrast, the Valley’s slopes were covered primarily by
northern hardwoods, and remain so today. Red Spruce has not regenerated on the
Valley’s floor, and thickets and openings dominate its present landscape.
Allard and Leonard (1952) provided an early description of the Valley’s
ecology:
“After the forest had been cut and its debris and all the humus layers destroyed
by drying and by fire, thousands of pounds of mixed grass seed were brought in
and sowed over the drier exposed soils of the area. At one time or another crops of
potato and other vegetables were attempted on a large scale on some of the better
soils near Glade Run. None of those efforts gave an adequate return and all traces
of these temporary cultural communities have disappeared.
In place of the tame grasses, timothy, orchard grass, red top and the clovers,
the wild oat grasses (Danthonia) have gained the ascendancy and dominate great
areas on the better upland soils. In the less elevated, wetter, more marshy areas,
wide stretches of hair-cap moss (Polytrichum), broken by patches of sphagnum
in the more boggy depressions, occupy the ground. In August these bogs become
1West Virginia University Extension Service, 29 Beechurst Avenue, Morgantown, WV
26506. 2Department of Civil and Environmental Engineering, West Virginia University,
PO Box 6103, Morgantown, WV 26506. 3Deceased; address correspondence to: rpreston@
comcast.net.
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2015 Vol. 14, Special Issue 7
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conspicuously whitened with almost pure stands of cotton grass (Eriophorum virginicum
L.).”
Exotic invasives and weeds are known problems, but native plants can also
become invasive. Again quoting Allard and Leonard (1952):
“Native weedy plants appear everywhere, including chiefly fireweed (Epilobium
angustifolium), bull thistle (Cirsium pumilum), brake (Pteridium aquilinum var.
latisculum), hay-scented fern (Dennstaedtia punctilobula), everlasting (Anaphalis
margaritacea), cudweed (Gnaphalium macounii Greene), goldenrods (Solidago
graminifolia (L.) Salisb., S. uliginosa Nutt., S. rugosa Ait.), aster (Aster umbellatus
Mill.), hawkweeds (Hieracium auranticum, H. pratense), buttercup
(Ranunculus acris L.), and ox-eye daisy (Chrysanthemum leucanthemum L. var.
pinnatifidum Lecoq. & Lamotte).”
Fortney (1975) later observed that Spiraea alba Du Roi (White Meadowsweet)
had also spread. Allard and Leonard (1952) further observed that,
“A biotic factor, represented by hundreds of head of grazing stock, is now producing
great modification in the grass and weed successions which naturally established
themselves following the complete destruction of the spruce forest.
These animals by their highly selective feeding upon the finer grasses, and
their avoidance of the ranker less palatable forbs, including the thistles, goldenrods,
asters, everlasting, and others, are tending to restrict the grasses and to favor
the extension of the latter. In some areas this has amounted to excessive grazing,
and the forbs have correspondingly increased. On the higher, more rocky ridges,
the latter completely control the situation.”
Evidence indicates that attempts to create cattle pastures were largely failures.
Agrostis gigantea Roth (Redtop Grass) is common today, likely the result of past
agricultural activities.
This paper updates the picture of the Valley’s exotic and invasive plant species
and presents an inventory with the goal of protecting the Valley’s rare plant
species and communities.
Results
We compiled the following list of the Valley’s exotic and invasive plant species
from several sources. Early publications include Allard and Leonard (1952)
and Fortney (1975). More recently, Michael (1993) and Norris (1997) updated the
Valley’s exotic flora. We combined the contents of the two latter papers and various
unpublished surveys into a category we classified as 1990+. In the following
list, the 3 designations of Allard, Fortney, and 1990+ indicate the source(s) that
reported the presence of each species.
Gymnospermae (conifers and others)
1990+ Pinus resinosa Sol. ex Aiton (Red Pine)
1990+ Pinus sylvestris L. (Scotch Pine)
1990+ Juniperus virginiana L. (Eastern Red Cedar)
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Angiospermae (flowering plants)
Poaceae
Fortney 1990+ Agrostis capillaris L. (Colonial Bent Grass)
Allard, Fortney 1990+ Anthoxanthum odoratum L. (Sweet Vernal Grass)
Allard Fortney, 1990+ Bromus commutatus Schrad. (Hairy Chess)
1990+ Bromus inermis Leyss. (Smooth Brome)
1990+ Bromus japonicus Thunb. ex Murr. (Japanese Brome)
Fortney 1990+ Dactylis glomerata L. (Orchard Grass)
Allard, Fortney, 1990+ Elymus repens (L.) Gould (Quackgrass)
Fortney, 1990+ Festuca pratensis Huds. (Meadow Fescue)
Allard, Fortney, 1990+ Holcus lanatus L. (Velvet Grass)
Allard, Fortney, 1990+ Hordeum jubatum L. (Foxtail Barley)
1990+ Lolium arundinaceum L. (Kentucky 31 Fescue)
Fortney Lolium perenne L. (Perennial Ryegrass)
Fortney, 1990+ Phalaris arundinacea L. (Reed Canary Grass)
Allard, 1990+ Phleum pratense L. (Timothy-grass)
Allard, Fortney, 1990+ Poa annua L. (Annual Bluegrass)
1990+ Poa compressa L. (Canada Bluegrass)
Allard, Fortney, 1990+ Poa pratensis L. (Kentucky Bluegrass)
1990+ Poa trivialis L. (Rough Bluegrass)
Iridaceae
1990+ Iris pseudoacorus L. (Yellow Iris)
1990+ Iris versicolor L. (Northern Blue Flag)
1990+ Iris virginica L. (Virginia Iris)
Liliaceae
1990+ Allium ampeloprasm L. (Wild Leek)
1990+ Asparagus officinalis L. (Asparagus)
Salicaceae
1990+ Populus alba L. (White Poplar)
Fortney Salix fragilis L. (Crack Willow)
Polygonaceae
Allard, Fortney Polygonum aviculare L. (Common Knotgrass)
Allard, Fortney Polygonum persicaria L. (Lady’s Thumb)
Fortney, 1990+ Rumex acetosella L. (Sheep’s Sorrel)
Allard, Fortney 1990+ Rumex crispus L. (Curly Dock)
Allard, Fortney 1990+ Rumex obtusifolius L. (Broad-leaved Dock)
Chenopodiaceae
Allard, Fortney Chenopodium album L. (Lamb’s Quarters)
Amaranthaceae
Allard, Fortney Amaranthus retroflexus L. (Red-rooted Pigweed)
Aizoaceae
Allard Fortney 1990+ Mollugo verticillata L. (Carpetweed)
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Portulacaceae
Fortney, 1990+ Portulaca oleracea L. (Common Purslane)
Carophyllaceae
Allard, Fortney, 1990+ Cerastium fontanum Baumg. (Mouse-ear Chickweed)
1990+ Cerastium glomeratum Thuill. (Clammy Chickweed)
1990+ Dianthus armeria L. (Deptford Pink)
Fortney Saponaria officinalis L. (Bouncing-bet)
Fortney, 1990+ Stellaria graminea L. (Grassleaf Starwort)
Ranunculaceae
Allard, Fortney, 1990+ Ranunculus acris L. (Tall Buttercup)
Fortney, 1990+ Ranunculus repens L. (Creeping Buttercup)
Berberidaceae
1990+ Berberis thunbergii DC. (Japanese Barberry)
Brassicaceae
Allard, Fortney, 1990+ Barbarea vulgaris R. Br. (Winter Cress)
Allard, Fortney Brassica rapa L. (Bird Rape)
Allard, Fortney Lepidium campestre (L.) W.T. Aiton (Field Pepperweed)
Allard, Fortney Lepidium densiflorum Schrad. (Common Pepperweed)
Rosaceae
Allard, Fortney Fragaria vesca L. (Woodland Strawberry)
1990+ Malus sylvestris (L.) Mill. (Crab Apple)
Fortney, 1990+ Potentilla recta L. (Sulphur Cinquefoil)
Fortney, 1990+ Rosa multiflora Thunb. ex Murr. (Multiflora Rose)
Fortney Rubus phoenicolasius Maxim. (Wineberry)
Fabaceae
1990+ Securigera varia (L.) Lassen (Crown Vetch)
1990+ Lespedeza cuneata (Dum. Cours.) G. Don (Sericea)
1990+ Lotus corniculatus L. (Birdsfoot Trefoil)
Fortney, 1990+ Medicago lupulina L. (Black Medic)
Fortney, 1990+ Melilotus officinalis (L.) Pall. (Yellow Sweet Clover)
Allard, Fortney Trifolium arvense L. (Rabbitfoot Clover)
Allard, Fortney, 1990+ Trifolium aureum Pollich (Yellow Hop Clover)
Fortney Trifolium campestre Schreb. (Low Hop Clover)
Fortney 1990+ Trifolium hybridum L. (Alsike Clover)
Fortney 1990+ Trifolium pratense L. (Red Clover)
Fortney, 1990+ Trifolium repens L. (White Clover)
Oxalidaceae
Allard, Fortney, 1990+ Oxalis stricta L. (Upright Yellow Wood-sorrel)
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Geraniaceae
1990+ Geranium columbinum L. (Long-stalked Crane’s-bill)
Malvaceae
Allard, Fortney, 1990+ Malva moschata L. (Musk Mallow)
Clusiaceae
Fortney, 1990+ Hypericum perforatum L. (Common St. John’s Wort)
1990+ Hypericum punctatum Lam. (Spotted St. John’s Wort)
Elaeagnaceae
Fortney, 1990+ Elaeagnus umbellata Thunb. (Autumn Olive)
Apiaceae
Allard, Fortney, 1990+ Daucus carota L. (Queen Anne’s Lace)
Fortney, 1990+ Pastinaca sativa L. (Parsnip)
Ericaceae
Allard Calluna vulgaris (L.) Hull (Heather)
Allard, 1990+ Erica tetralix L. (Cross-leaved Heath)
Boraginaceae
Fortney, 1990+ Echium vulgare L. (Viper’s Bugloss)
Lamiaceae
Allard, Fortney Galeopsis bifida Boenn. (Splitlip Hemp-nettle)
Fortney, 1990+ Glechoma hederacea L. (Ground-ivy)
1990+ Mentha x piperita L. (Peppermint)
Fortney, 1990+ Prunella vulgaris L. (Common Self-heal)
Solanaceae
Fortney, 1990+ Solanum dulcamara L. (Bittersweet Nightshade)
Scrophulariaceae
Allard, Fortney, 1990+ Linaria vulgaris Mill. (Butter-and-Eggs)
Fortney 1990+ Verbascum thapsus L. (Great Mullein)
Allard, Fortney, 1990+ Veronica officinalis L. (Common Speedwell)
Fortney Veronica serpyllifolia L. (Thyme-leaved Speedwell)
Plantaginaceae
Fortney, 1990+ Plantago lanceolata L. (Ribwort Plantain)
Allard, Fortney, 1990+ Plantago major L. (Greater Plantain)
Rubiaceae
Fortney, 1990+ Galium album Mill. (White Bedstraw)
Dipsacaceae
Allard, Fortney 1990+ Dipsacus fullonum L. (Fuller’s Teasel)
Asteraceae
Fortney, 1990+ Achillea millefolium L. (Yarrow)
Fortney Arctium minus (Hill) Bernh. (Lesser Burdock)
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1990+ Cichorium intybus L. (Common Chicory)
Allard, Fortney, 1990+ Cirsium arvense (L.) Scop. (Canada Thistle)
Allard, Fortney, 1990+ Cirsium vulgare (Savi) Ten. (Common Thistle)
Allard, Fortney, 1990+ Crepis capillaris (L.) Wallr. (Smooth Hawksbeard)
Allard, Fortney Hieracium auranticum L. (Orange Hawkweed)
Fortney Hieracium pilosella L. (Mouse-ear Hawkweed)
Allard, Fortney, 1990+ Hieracium caespitosum Dumort (Field Hawkweed)
Allard, Fortney, 1990+ Leucanthemum vulgare Lam. (Ox-eye Daisy)
Fortney, 1990+ Matricaria discoidea DC. (Pineapple Weed)
Allard, Fortney Sonchus arvensis L. (Field Sow Thistle)
1990+ Sonchus oleraceus L. (Annual Sow Thistle)
Allard, Fortney, 1990+ Taraxacum officinale F.H. Wigg (Common Dandelion)
Allard, Fortney Tragopogon dubius Scop. (Goat’s Beard)
1990+ Tragopogon pratensis L. (Showy Goat’s Beard)
1990+ Tussilago farfara L. (Coltsfoot)
Of the 106 species listed above, most are not likely to outcompete or displace
the Valley’s indigenous plants. Many of these invasive plants exist only in disturbed
sites such as roadsides, golf courses, yards, and farmlands. Redtop Grass,
a native grass that was introduced for pastures, is common in the Valley and probably
will continue to persist at present levels. Other grasses and weeds that seem
to have reached balanced populations at fairly low levels are Velvet Grass, Sweet
Vernal Grass, Timothy-grass, Tall Buttercup, Curly Dock, Broad-leaved Dock,
Upright Yellow Wood-sorrel and Sheep Sorrel, Queen Anne’s Lace, Common
Dandelion, Smooth Hawksbeard, Orange and Field Hawkweeds, Ox-eye Daisy,
and Fuller’s Teasel. Except where human activity occurs regularly, the clovers
listed as common by Allard and Leonard (1952) have largely disappeared from
the Valley’s floor. Reed Canary Grass was found by Allard and Leonard (1952)
near Davis, was uncommon in Fortney’s mid-1970s survey, and today often
grows as invasive patches. Strausbaugh and Core (1977) considered Reed Canary
Grass to be native along the Ohio River, so this grass should be recognized as an
invasive threat to the Valley’s wet grasslands and riverbanks.
Other exotic plant species that are present in the Valley and that could be
aggressively invasive include White Bedstraw, Canada Thistle, Bittersweet
Nightshade, Crown Vetch, Common Chicory, Viper’s Bugloss, Yellow Iris, and
Wineberry. We believe that non-native shrubs and trees with a high potential to
become invasive are Red Pine, Scotch Pine, Lonicera morrowii A. Gray (Morrow’s
Honeysuckle), Multiflora Rose, and Japanese Barberry. At least three large
clonal colonies of White Poplar, which invades through root suckers, are growing
in the Valley and should be exterminated. Plantings of Scotch and Red Pines
should also be eradicated.
Two unusual exotics, Heather and Cross-leaved Heath, grow near the divide
between the Valley and Stony River. They were discovered by Allard in
1942 (Clarkson 1958). Heather has apparently been extirpated by local people;
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Cross-leaved Heath continues to persist but is not spreading. Betula papyrifera
var. cordifolia (Regel) Fern. (Mountain Paper Birch), which may be introduced
or native, also occurs at this site.
A comprehensive program to prevent the establishment of highly invasive
plants in the Valley should be implemented. Ailanthus altissima (Mill.) Swingle
(Tree-of-heaven), Phragmites australis (Cav.) Trin. ex Steud. (Common Reed),
Microstegium vimineum (Trin.) A. Camus (Japanese Stilt Grass), Centaurea
maculosa Lam. (Spotted Knapweed), and Typha angustifolia L. (Narrow-leaved
Cattail) have not been documented in the Valley, but they are highly invasive
exotics (NHP 2009, Stevens and Hoag 2006, Strausbaugh and Core 1977) that, if
allowed to become established, would degrade native biodiversity and be costly
to eradicate or even control.
Logging continues to be a major economic activity on the slopes forming
the Valley’s northern end and around Big Cove, which lies in the headwaters
of the Little Blackwater River. Home and commercial construction continues
slowly in the Valley’s southern end and will likely accelerate when sewage and
water problems are resolved. Projects that move earth, including landscaping,
road reclamation, forestry operations, and developing recreational access sites
will create the most habitat for exotic plant establishment. Although the Valley
is not presently infested with any highly invasive exotic plants, the potential for
them to overrun disturbed habitats is real.
Control of Invasive Plants
Monitoring existing and newly documented invasive exotic and native plants
is the essential first step to control invasive plants. Towards that end, conditions
in the Valley pose unique challenges. Land ownership is split among federal and
state natural resource agencies, individual landowners, and corporate entities.
Further, there have been long-standing conflicts between pro- and anti-development
interests. Other factors in management and planning include the presence
of rare plant species, unusual plant communities, and endangered animals.
To work toward solutions, we believe that a consortium of people with vested
interests in the Valley’s natural resources should be organized to undertake
education, monitoring, control, and eradication efforts. A partial list of these
stakeholders includes Timberline Resort, Black Bear Woods, Deerfield Village
Resort, the Valley’s realtors and riding stables, USDA Forest Service-Monongahela
National Forest, US Fish and Wildlife Service-Canaan Valley National
Wildlife Refuge, West Virginia (WV) Department of Natural Resources-Canaan
Valley State Park and Resort, WV Department of Highways, WV Department
of Agriculture, Allegheny Energy, Western Pocahontas Properties, The Nature
Conservancy, WV Native Plant Society, and individual landowners.
When an invasive plant species is targeted for management actions, managers
will have to determine the best way to control each species. Mechanical, chemical
(herbicides), and biological controls, or some mix of the three, are options
to control or eradicate invasive plant populations. Sources of information on
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control methods include printed materials, person-to-person consultations, and
the websites of universities, non-governmental organizations like The Nature
Conservancy, and federal and state natural resource agencies such as the National
Park Service and USDA Natural Resource Conservation Service.
Literature Cited
Allard, H.A., and E.C. Leonard. 1952. The Canaan and the Stony River valleys of West
Virginia, their former magnificent spruce forests, their vegetation and floristics today.
Castanea 17:1–60.
Clarkson, R.B. 1958. Scotch Heather in North America. Castanea 23:119–130.
Fortney, R.H. 1975. The vegetation of Canaan Valley, West Virginia: A taxonomic and
ecological study. Ph.D. Dissertation, West Virginia University, Morgantown, WV.
235 pp.
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States,
Canada, and Greenland, 2nd Edition. Vol. 1—Checklist. Timber Press, Portland, OR.
622 pp.
Michael, E.D. 1993. An evaluation of the wetland and upland habitats and associated
wildlife resources in southern Canaan Valley. Final report submitted to the Canaan
Valley Task Force. West Virginia University, Morgantown, WV. 170 pp.
Natural Heritage Program (NHP). 2009. Invasive plant species of West Virginia. West
Virginia Division of Natural Resources, Elkins, WV. Available online at http://www.
wvdnr.gov/wildlife/Handout%20Invasive%20Plants%20of%20WV%202009.pdf.
Accessed 30 September 2014.
Norris, S.J. 1997. Vegetation study of the grasslands of Canaan Valley National Wildlife
Refuge. Technical Report, WV Department of Natural Resources, Elkins, WV.
Stevens, M., and C. Hoag. 2006. Narrow leaf Cattail, Typha angustifolia L. Plant Guide,
USDA Natural Resources Conservation Service. Available online at http://plants.
usda.gov/plantguide/pdf/cs_tyan.pdf. Accessed 30 September 2014.
Strausbaugh, P.D., and E.L. Core. 1977. Flora of West Virginia, 2nd Edition. Seneca
Books, Grantsville, WV. 1079 pp.