Family: Anacardiaceae
Sumac
William S. Alverson
Key to Wisconsin Rhus
Author: John G. Zaborsky
- 1a.Leaflets 3; flowers in small, clustered inflorescences, opening before the leaves R. aromatica
- 1b.Leaflets 7–23; flowers in large panicles; opening after the leaves 2
- 2a.Rachis winged; leaflets entire (rarely toothed) R. copallina
- 2b.Rachis not winged; leaflets toothed their entire length 3
- 3a.New branches and petioles glabrous; hairs on fruit 0.5 mm or shorter, clavate; leaflets glabrous abaxially (or nearly so) R. glabra
- 3b.New branches and petioles densely pubescent with both short and long hairs, the latter 1–2 mm long; hairs on fruit 1–2 mm long, tapering to a sharp tip; leaflets pubescent abaxially R. typhina
Rhus glabra and R. typhina are well known and common clonal shrubs forming large stands along roadsides and in fields. Rhus copallina is also clonal but is far less common. All four of our species have beautiful fall color.
