Anacardiaceae. 



187 



sylvestris. Shirasawa, 233, pi. 2. R. Toxicodendron (includ- 

 ing R. radicans). Blakeslee & Jarvis, 528; Brendel, pi. 3; 

 Hitchcock (3), 11, (4), 135, f. 35-36; Schneider, f. 79; Shira- 

 sawa, 259, pi. 1. R. trichocarpa. Shirasawa, 233, pi. 1. R. 

 typhina (R. hirta). Blakeslee & Jarvis, 342, 526, pi.; Bose- 

 mann, 55; Greene, Ottawa Naturalist. 24:139; Schneider, f. 

 79. R. vernicifera. Shirasawa, 232, pi. 1. R. Vernix. Blakes- 

 lee & Jarvis, 333, 334, 528, pi. 



Rhus. Sumach. 

 (Family Anacardiaceae). 



Shrubs, exceptionally climbing 

 by aerial roots or becoming small 

 open trees; with milky sometimes 

 very poisonous sap: deciduous as 

 to our species. Twigs round or 

 bluntly 3-sided, sometimes fluted, 

 slender to very stout: pith rather 

 large, roundish, continuous, often 

 pink or brown. Buds moderate or 

 rather small, solitary, sessile, 

 round-ovoid, hairy and indistinct- 

 ly scaly or with 3 or 4 evident 

 scales, the end-bud often lacking. 

 Leaf-scars alternate, round or 

 crescent-shaped, or C-shaped and 

 encircling the buds, more or less 

 raised: bundle-traces rather nu- 

 merous in the lower half of the 

 round leaf-scars but sometimes in 

 3 more or less evident groups or 

 3 or 5 to 9 single scars or groups 

 in the narrower leaf-scars: stipule-scars lacking. 



The fragrant sumach has a very distinctive type of leaf- 

 fall and the generic name Schmaltzia has been used exclu- 



