Western poison ivy is a native species that is found across the US and Canada (excluding a cluster of states in the southeastern US, Alaska, California, Nunavut, and the Northwest Territories) (USDA 2010). Disjunct populations are reported from mountaintops of the central Appalachians (McMurray 1988). In British Columbia, it may be encountered in south-central regions and particularly in the Okanagan Valley. Throughout its range, it occurs on a variety of habitats ranging from riverbanks and lakeshores at low elevations to subalpine sites. In BC, it is most often noticed along river and lake shorelines (e.g. Vaseaux Lake) where it is moderately abundant. It is a distinctive, usually erect, rhizomatous small shrub up to 2 m in height. It most often occurs as a subshrub (McMurray 1988). Branching is simple. It has three shiny, pointed leaves and numerous monecious flowers occur in dense clusters in the leaf axils. Berries are white, sometimes greenish-yellow. Leaves often appear slightly drooping and exude milky sap when broken or cut. Western poison ivy can cause dermatological reactions when touched, resulting in an itchy rash, and should not be handled.
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McMurray, Nancy E. 1988. Toxicodendron rydbergii. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2014. E-Flora BC:
Electronic Atlas of the Plants of British Columbia [eflora.bc.ca]. Lab for
Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
5/5/2015 6:13:32 AM
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