ANACARDIACEAE: Cashew Family
KEY TO SPECIES OF TOXICODENDRON
DANGER: ALL SPECIES CAN BE POISONOUS TO THE TOUCH
1. Leaflets 7-15 (never 7 on all leaves), almost always entire, rarely with 1-few coarse teeth or lobes ........... T. vernix
1. Leaflets 3, rarely 5 or even less likely 7, either entire, undulate, notched, lobed, and/or serrate .......... 2
2. Leaflets entire, undulate, or round-lobed. Fruits hairy ................................................................ 3
3. Leaflets mostly obtuse or rounded at apex, tufts of hairs absent from vein axils on lower surface ............. T. pubescens
3. Leaflets acute to acuminate at apex, tufts of hairs present in vein axils on lower surface ................ T. radicans ssp. radicans
2. Leaflets mostly notched or serrate or occasionally with one lobe on each edge. Fruits glabrous ................ 4
4. Leaflet underside with a dense covering of hairs, the hairs erect .................................................... T. radicans ssp. pubens
4. Leaflet underside glabrous or, if hairy, hairs appressed ..................................................... 5
5. Leaflets ovate to lanceolate; petiole finely hairy ..................................................... T. radicans ssp. negundo
5. Leaflets nearly orbicular to broadly ovate; petiole glabrous ........................ T. rydbergii