Toxicodendron radicans, T. rydbergii; poison ivy [Anacardiaceae]  Climbing, woody vine (T. radicans), or small rhizomatous shrub (T. rydbergii) with very small (1/8" wide) green flowers in inconspicuous branching axillary clusters.  Small (¼") fruit grayish or yellowish white.  Leaves compound but variable in appearance, with 3 entire or coarsely toothed leaflets, sometimes shiny, sometimes not.  Open woods, wood edges and openings, fencerows, floodplains, and prairies.  Flowers in late spring and early summer.  T. vernix (poison sumac) is a related shrub found in swamps throughout much of the state.  All parts poisonous to the touch in all seasons.  [092]