Rhus are readily recognizable dioecious shrubs or small trees which, in female plants, bear red fruits with glandular hairs in large panicles (small in R. aromatica).

1. Leaflets 3, with 3-6 large teeth per side; flowers in small (ca. 1 cm) dense inflorescences on short lateral shoots (± coalescing in fruit), opening before the leaves.

R. aromatica

1. Leaflets 7-23, entire or with 6-15 teeth per side; flowers in large inflorescences, opening after the leaves.

2. Rachis ± winged, especially between distal leaflets; leaflets usually entire, occasionally with scattered teeth near the apex, rarely more toothed.

R. copallina

2. Rachis not winged; leaflets toothed to the base.

3. Petioles and new branches glabrous or nearly so, typically with a glaucous 'bloom'; hairs on fruit less than 0.5 mm long, mostly clavate to obovoid; leaflets glabrous beneath (or with a few hairs) [see text for intermediate plants].

R. glabra

3. Petioles and new branches with ± dense pubescence including many long (mostly 1-2 mm) straight hairs, not glaucous; hairs on fruit mostly 1-2 mm long, tapering to a sharp point (very short obovoid hairs may also be present); leaflets pubescent beneath, at least on veins.

R. typhina