84 ANACABDIACEAE 



RHUS. Sumach. 



Deciduous shrubs or straggling small trees with aromatic 

 resinous or milky sap; soft reddish or greenish wood with 

 small ducts, decreasingly smaller or in wavy transverse pat- 

 terns in the summer growth, and fine medullary rays; usually 

 stout roundish or 3- or 5-sided twigs with large pith of similar 

 shape; alternate somewhat raised triangular or C-shaped large 

 leaf-scars; roundish sessile buds; pinnate leaves with mostly 

 toothed or sometimes incised lanceolate leaflets; small often 

 imperfect polypetalous yellowish flowers in axillary or termi- 

 nal clusters; and small often dry drupe-like fruits. The true 

 sumachs are sometimes separated as Schmaltzia, and the 

 name Toxicodendron is used for the poisonous group. 



1. Leaflets three. 2. 

 Leaflets 5 or more. 4. 



2. Fruit red, pubescent. (Fragrant sumach). R. canadensis. 

 POISONOUS. Fruit white, glabrous. 3. 



3. Prostrate or climbing by roots: leaflets thin, 



scarcely lobed. (Poison ivy). R. radicans. 



Bushy: leaflets firm, often deeply lobed. 



(Poison oak). R. Toxicodendron. 



4. POISONOUS. Fruit white, glabrous: leaflets entire: 



rachis not winged. (Poison sumach). R. Vernix. 



Fruit red, pubescent. 5. 



5. Rachis winged between the leaflets. 6. 

 Rachis not winged. 7. 



6. Leaflets mostly entire, glossy, glabrate beneath. R. copallina. 

 Leaflets toothed, hairy beneath. R. javanica. 



7. Glabrous. 8. 

 Hairy. 9. 



8. Leaflets serrate. (Smooth sumach). R. glabra. 

 Leaflets deeply cut. R. glabra laciniata. 



9. Leaflets serrate. (Staghorn sumach). R. typhina. 

 Leaflets deeply cut. R. typhina laciniata. 

 Leaflets twice-divided. R. typhina dissecta. 



