ANACARDIACEAE: Cashew Family
KEY TO SPECIES OF RHUS
1. Leaflets 3 ..................................................................................................................................... 2
2. Largest terminal leaflet on longest twig 28-112 X 15-79 mm .................................. R. aromatica
2. Largest terminal leaflet on longest twig 15-29 X 10-19.5 mm ................................... R. trilobata
1. Leaflets 7-31, more if twice-compound .......................................................................................... 3
3. Twigs of year 1 glabrous; leaf rachis wingless .......................................................... R. glabra
3. Twigs of year 1 hairy, hairs sometime minute; leaf rachis winged or wingless ............................. 4
4. Plants to 1 m, generally only to 60 cm; leaflets mostly over half as wide as long; teeth to 5.5 mm high ................ R. michauxii
4. Plants 0.4-16 m; leaflets less than half as wide as long; teeth to 2.5 mm high ................................................... 5
5. Twigs of year 1 with curved glandless grayish-tan hairs 0.02-1 mm, sometimes hiding surface; leaf rachis winged, sometimes minutely so ................................................................................................. R. copallina
5. Twigs of year 1 with straight glandless hairs minute to 2.5 mm, glandular hairs to ca 0.5 mm sometimes present, surface not hidden; leaf rachis not winged ..................................... R. typhina