Rhus

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; 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; 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

All species found in Rhus

Rhus aromaticaFRAGRANT SUMAC 
Rhus copallinaSHINING SUMAC, DWARF SUMAC, WINGED SUMAC 
Rhus glabraSMOOTH SUMAC 
Rhus typhinaSTAGHORN SUMAC 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 13, 2017. http://www.michiganflora.net/genus.aspx?id=Rhus.