Toxicodendron radicans (Linnaeus) Kuntze var. radicans . Phen: Late Apr-May; Aug-Oct. Hab: In a wide range of habitats, including mesic forests, rock outcrops, swamp forests, brackish marshes, open areas, disturbed ground, usually in more mesic to hydric sites than T. pubescens, and particularly common in areas with fertile soils, such as bottomlands or over calcareous rocks or calcareous sands (as in maritime forests). Dist: NS south to s. FL (and the Bahamas), west to e. TX, inland to VT, c. PA, WV, KY, and AR.
Origin/Endemic status: Native
Taxonomy Comments: Var. radicans is the typical poison ivy of the Atlantic and Gulf Coastal Plain, rarely found west of the Appalachians.
Other Comments: Toxicodendron radicans var. radicans is normally a vine, climbing by adventitious roots, and can attain diameters of 10 cm and climb to the crowns of forest trees. It can also resemble T. pubescens in habit, producing numerous meter-high upright stems from rhizomes.
Synonymy: = Va; = Toxicodendron radicans (L.) Kuntze ssp. radicans – K1, K3, K4, Mo2, NE, NY; < Rhus radicans L. – Bah, RAB; > Rhus radicans L. var. radicans – F, G, WV; < Rhus radicans L. var. vulgaris (Michx.) DC. – Tx; > Rhus radicans L. var. vulgaris (Michx.) DC. – WV; > Rhus radicans L. var. vulgaris (Michx.) DC. – F, G; < Toxicodendron radicans (L.) Kuntze – Ar, Fl4, GW2, Mi, Pa, S, Tn, W, WH3; < Toxicodendron radicans (L.) Kuntze var. radicans – C, Il, NeUS