ANACARDIACEAE 153 



ANACARDIACEAE 

 The Sumac Family 



The sumacs, shrubs or trees with alternate, simple or pin- 

 nately compound leaves without stipules, bear polygamous, 

 monoecious or dioecious flowers in panicles, spikes or racemes. 

 The flowers are regular and have 3 to 5 distinct sepals, 3 to 5 

 petals, and 3 to 5 stamens alternate with the petals. The ovary 

 consists of 4 to 5 united or nearly distinct carpels, and the 

 styles are likewise either united or distinct. The fruit is a drupe 

 or berry which contains a solitary seed. 



There are about 60 genera and 3,000 species in this family. 

 These are most abundant in warm or tropical regions, but the 

 range of a few extends into the temperate zone. Three genera 

 are native in northeastern North America, but only one grows 

 in Illinois. 



RHUS (Tournefort) Linnaeus 

 The Sumacs 



The sumacs are shrubs, trees or vines, some poisonous and 

 some not, w^ith alternate, odd-pinnate leaves, which may be en- 

 tire or toothed. The greenish-white or yellow flowers are 

 polygamous or dioecious and occur in terminal panicles. Sepals, 

 petals and stamens commonly are 5 in number. The ovary is 

 1-celled, and the fruit is a small drupe containing a smooth 

 stone. 



Key to the Sumac Species 



Leaflets 3 per leaf. 



Petioles of the leaves generally less than ll4 inches long, 



the fruit red and densely hairy R. aromatica, p. 159 



Petioles generally more than 1\4 inches long, the fruit pale 



green and usually smooth R. radicans, p. 159 



Leaflets more than 3 per leaf. 

 Branchlets pubescent. 



Rachis of the leaf winged, leaflets almost entire but some- 

 times with a few coarse teeth R. copallina, p. 154 



Rachis of the leaf not winged, leaflets regularly serrate 



to the base R. typhina, p. 1 54 



Branchlets smooth. 



Branchlets angled, leaves serrate, fruit red. . .R. glabra, p. 156 

 Branchlets round, leaves entire or nearly so, fruit pale 



green to almost colorless R. vernix, p. 158 



