CHAPTER XLV: THE SUMACHS AND THE 



SMOKE TREE 



Family Anacardiace^ 



I. Genus RHUS, Linn. 



Small trees or shrubs with stout, pithy branchlets, and 

 viscid, usually milky, juice. Leaves alternate, usually pinnately 

 compound. Floivers minute, greenish, polygamo-dioecious, in 

 compound panicles. Fruit a small, dry drupe. 



KEY TO SPECIES 



A. Leaves pinnate, of 9 to 31 leaflets, deciduous. 



B. Fruit whitish, in loose, drooping, axillary panicles. 



(R. Vernix) poison sumach 

 BB. Fruit red, in erect, compact terminal panicles. 



C. Branches, fruit clusters and leaf stalks densely 

 hairy; leaflets 11 to 31 ; juice milky. 



(/?. hirta) staghorn sumach 

 CC. Branches, fruit clusters and leaf stalks pubescent; 

 rachis v/inged; leaflets 9 to 21 ; juice watery. 



{R. copallina) dwarf sumach 

 A A. Leaves simple, evergreen. 



{R. integrijolia) western sumach 



The sumachs form a temperate zone genus of a great tropical 

 fam.ily, comprising fifty genera and 400 species. There are about 

 120 species of the genus Rhus; they are most abundant in South 

 Africa. Sixteen species are found in North America, only four 

 of which are ever trees. Of these, none compare in economic 

 importance with the sumach cultivated in southern Europe, 

 whose leaves contain 25 to 30 per cent, of tannic acid, and are 

 regularly gathered and dried, and used in the tanning of fine 

 leathers. The pistachio-nut tree, from Asia Minor, now cultivated 

 in southern California, is a relative of our roadside sumachs, as 

 is also the turpentine tree of southern Europe. They belong to 

 the genus Pistacia, and are both commercially important. 



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