Family: Araliaceae (Ginseng Family)
Duration and Habit: Perennial Vine
Evergreen woody vine climbing to 90 feet (28 m) by clinging aerial roots and trailing to form dense ground cover. Thick dark-green leaves with whitish veins and three to five pointed lobes when juvenile. Maturing at about 10 years into erect plants or branches with unlobed leaves and terminal flower clusters that yield purplish berries. Toxic to humans when eaten and triggering dermatitis in sensitive individuals.
Ecological Threat: English ivy is a vigorous growing vine that impacts all levels of disturbed and undisturbed forested areas, growing both as a ground cover and a climbing vine. As the ivy climbs in search of increased light, it engulfs and kills branches by blocking light from reaching the host tree?s leaves. Branch dieback proceeds from the lower to upper branches, often leaving the tree with just a small green ?broccoli head.? The host tree eventually succumbs entirely from this insidious and steady weakening. In addition, the added weight of the vines makes infested trees much more susceptible to blow-over during high rain and wind events and heavy snowfalls. Trees heavily draped with ivy can be hazardous if near roads, walkways, homes and other peopled areas. On the ground, English ivy forms dense and extensive monocultures that exclude native plants. English ivy also serves as a reservoir for Bacterial Leaf Scorch (Xylella fastidiosa), a plant pathogen that is harmful to elms, oaks, maples and other native plants.
Biology & Spread: English ivy spreads locally through vegetative growth and new plants can grow from cut or broken pieces of stems that are able to root in the soil. It disperses longer distances via seed which is carried to new areas by frugivorous birds including the Cedar Waxwing, Northern Robin, Stellar Jay, Mockingbird, European Starling, and House Sparrow.
History: Introduced from Europe in colonial times. Traditional ornamental and still widely planted as an ornamental. Source of varnish resin, dye, and tanning substances.
U.S. Habitat: Thrives in moist open forests, but adaptable to a range of moisture and soil conditions, including rocky cliffs. Shade tolerance allowing early growth under dense stands, but becoming adapted to higher light levels with maturity. Avoids wet areas. Amasses on infested trees, decreasing vigor, and increasing chance of windthrow. Serves as a reservoir for bacterial leaf scorch that infects oaks (Quercus spp.), elms (Ulmus spp.), and maples (Acer spp.). Spreads by bird-dispersed seeds and colonizes by trailing and climbing vines that root at nodes. Drupes mildly toxic, discouraging over consumption by birds.
U.S. Nativity: Introduced to U.S.
Native Origin: Europe to Caucasus (Alfred Rehder, Manual of Cultivated Trees and Shrubs: Hardy in North America, The MacMillan Co., New York (1967)); Europe, w. Asia, No. Africa (Bailey, L.H. and E.Z. Bailey, Hortus Third: A Concise Dictionary of Plants Cultivated in the United States and Canada, MacMillan Publishing Co., Inc., New York , (1977).); NatureServe Explorer
U.S. Present: AL, AZ, CA, FL, GA, HI, IL, IN, KY, LA, MA, MD, MI, MO, MS, NC, NJ, NY, OH, OR, PA, SC, TN, TX, UT, VA, WA, WV
Distribution: English ivy has been reported to be invasive in natural areas in 18 states and the District of Columbia.
List All Observations of Hedera helix reported by Citizen Scientists
A wide variety of attractive and ecologically adapted and beneficial native plants can be substituted for English ivy. Select plants adapted to the level of light available on the site (i.e., full sun, shade, part-shade). Plants that will eventually spread to cover an area of ground include flowering plants like eastern prickly pear cactus (Opuntia humifusa), blue phlox (Phlox divaricata), wild ginger (Asarum canadense), Allegheny spurge (Pachysandra procumbens), and green and gold (Chrysogonum virginianum); ferns like Christmas fern (Polystichum acrostichoides), northern maidenhair fern (Adiantum pedatum), northern lady fern (Athyrium filix-femina), sensitive fern (Onoclea sensibilis), and cinnamon fern (Osmunda cinnamomea); grasses like red fescue (Festuca rubra), wild oats (Chasmanthium latifolium), bottlebrush grass (Elymus hystrix) and switch grass (Panicum virgatum); and sedges like Pennsylvania sedge (Carex pennsylvanica) and tussock sedge (Carex stricta). Native vines that are good replacements for English ivy include trumpet creeper (Campsis radicans), Virginia creeper (Parthenocissus quinquefolia), passionflower vine (Passiflora lutea), Dutchman's pipe (Aristolochia macrophylla), and native wisteria (Wisteria frutescens)*.
* If you wish to plant wisteria, make certain that it is the native species. Two commonly planted ornamental wisterias, Chinese wisteria (Wisteria sinensis) and Japanese wisteria (Wisteria floribunda), are exotic and aggressive invaders. Please consult the native plant society in your state for more information on species native to your particular area.
Animal Poison Control Center. http://www.aspca.org/toxicplants/M01879.htm
Assiut University (Egypt). English ivy. http://www.aun.edu.eg/distance/pharmacy/poison/hedera.htm
Collins, Christi. 1994. Some notes on Hedera helix The English ivy. The Nature Conservancy.
Czarapata, E. J. 2005. Invasive plants of the upper midwest: an illustrated guide to their identification and control. The University of Wisconsin Press. 215 pp.
Dirr, Michael A. 1990. Manual of woody landscape plants: their identification, ornamental characteristics, culture, propagation and uses. Stipes Publishing Company, Champaign, IL.
Fernald, M.L. 1970. Gray's Manual of Botany. Eighth ed. D. Van Nostrand Co., New York, N.Y. p.1078.
Harty, Francis M. 1993. How Illinois kicked the exotic species habit. In B.N. McKnight (ed.), Biological Pollution. Indiana Academy of Science, Indianapolis, Indiana. Pp. 195-209.
Holloran, P., A. Mackenzie, S. Ferrell, & D. Johnson. 2004. The Weed Workers
APWG WeedUS Database
Miller, J.H. 2003. Nonnative invasive plants of southern forests: a field guide for identification and control. Gen. Tech. Rep. SRS-62. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 93 pp (USDA SRS).
Swearingen, J., K. Reshetiloff, B. Slattery, and S. Zwicker. 2002. Plant Invaders of Mid-Atlantic Natural Areas. National Park Service and U.S. Fish & Wildlife Service, 82 pp.
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