Eastern Poison-oak (Toxicodendron pubescens) is found in sandy woods in the eastern United States from Long Island and New Jersey south to northern Florida and west to West Virginia, southern Missouri, southern Kansas, and Texas (Gleason and Cronquist 1991). Poison-oak and its close relatives are well-known for possessing skin-irritating oil (urushiol), which can cause severe allergic reactions in humans.
The taxonomy and nomenclature of North American Toxicodendron has been in flux for over a century, largely due to confusing within-species variation in growth form, leaf and leaflet shape, and other features (e.g., Gillis 1971; Gartner 1991). This has resulted in an abundance of synonyms, but five species are now generally recognized: Common Poison-ivy (T. radicans), Western Poison-ivy (T. rydbergii), Eastern Poison-oak (T. pubescens), Western Poison-oak (T. diversilobum), and Poison-sumac (T. vernix) (Senchina 2006). Eastern Poison-oak is a suberect shrub, usually not exceeding 1 m in height, with 3-leafleted leaves (Gleason and Cronquist 1991).
Senchina (2008) reviewed the literature on animal and fungal associates of Toxicodendron in North America with a particular eye toward identifying potential biological control agents. Interest in finding new ways to control poison-ivy and its relatives may increase in coming years given data suggesting that these plants may become more abundant and more ‘‘toxic’’ in the future, potentially affecting global forest dynamics and human health (Mohan et al. 2006).
- Mohan, J.E., L.H. Ziska, W.H. Schlesinger, R.B. Thomas, R.C. Sicher, K. George, and J.S. Clark. 2006. Biomass and toxicity responses of poison ivy (Toxicodendron radicans) to elevated atmospheric CO2. Proceedings of the National Academy of Sciences (U.S.A.) 103(24): 9086-9089.
- Gartner, B.L. 1991. Is the climbing habit of poison oak ecotypic? Functional Ecology 5: 696-704.
- Gillis, W.T. 1971. The systematics and ecology of poison-ivy and the poison-oaks (Toxicodendron, Anacardiaceae). Rhodora 73: 72-159, 161-237, 370-443, and 465-540.
- Gleason, H.A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada, 2nd ed. The New York Botanical Garden, Bronx, NY.
- Senchina, D.S. 2006. Ethnobotany of poison ivy, poison oak, and relatives (Toxicodendron spp., Anacardiaceae) in America: Veracity of historical accounts. Rhodora 108(935): 203-227.
- Senchina, D.S. 2008. Perspectives in Plant Ecology. Fungal and animal associates of Toxicodendron spp. (Anacardiaceae) in North America. Evolution and Systematics 10: 197-216.