Muir Park State Natural Area, Marquette Co., WI
Quite a number of Western poison oak plants were seen in single stemmed erect form, bring forth new leaves for the first time this year within the last two weeks. They were specifically sighted in the riparian zone, although they are also certainly found higher up in the oak woodland.
These newly emerged leaves of three have just appeared in vine form clinging to an oak tree within this mixed oak woodland.
Toxicodendron a genus of flowering plants in the sumac family, Anacardiaceae. It contains woody trees, shrubs and vines, including poison ivy, poison oak, and the lacquer tree. All members of the genus produce the skin-irritating oil urushiol, which can cause a severe allergic reaction. The generic name is derived from the Greek words τοξικός (toxikos), meaning "poison," and δένδρον (dendron), meaning "tree".