362 



COLLEGE BOTANY 



The genus Rhus contains the common poison ivy or poison 

 oak (R. toxicodendron) , the poison sumach (R. venenafo), the 

 common sumach (R. glabra), and several other species. 



Products from some of the species of this genus are used 

 for the manufacture of high-grade tannins, in the making of 

 dyes, varnishes and inks, and in medicine. 



( Horse-chestnut and Maple Family). Trees 



FIG. 204. Maple. 



or shrubs; leaves simple or compound and opposite flowers 

 mostly asymmetrical, often irregular, usually polygamous or 

 dioecious ; sepals four or five ; petals four or five, and sometimes 

 wanting; stamens five to ten, inserted on a fleshy disc; ovary 

 two- or three-chambered, but only one ovule in each chamber 

 maturing. A large and diversified family containing many im- 

 portant trees (Fig. 204). 



The genus! Acer includes the maples (Fig. 205) ; the genus 

 SEsculus, the horse-chestnut and buckeye ; and the genus Staphy- 

 lea, the bladder nut. 



The maples will be recognized as the most important mem- 

 bers of this family. They are among the most prominent of our 



