336 COLLEGE BOTANY 



The fig (Ficus sarica) (Fig. 171), the rubber plant (F. elas- 

 tica\ the banyan tree (F. bengal en-sis], and the hemp (Cannabis 

 sativa) belong to this family. 



POLYGONACE^E (Buckwheat Family). Herbs; stems with 

 swollen joints ; leaves alternate with sheathing stipules ; flowers 



perfect (or polygamous) ; 

 calyx three- to six-cleft and 

 more or less persistent, the 

 inner circle sometimes peta- 

 loid ; stamens one to nine 

 (sometimes more) ; ovary one- 

 chambered with two or three 

 styles ; fruit a one-celled, three- 

 or four-angled or sometimes 

 winged achene. 



The common buckwheat 

 (Fagopyrum escidentum and 

 other species) (Figs. 172, 

 173) is a native of Asia which 

 has been widely distributed 

 throughout the world. 



The rhubarb or pie-plant 

 (Rheum rhaponticum and 



FIG. 174. The table beet. ' \ 11 i 



other species) is a well-known 



garden plant which probably originated in Asia. It is also used 

 in medicine. 



This family also includes the common docks and sorrels 

 (Rumex sp.), the grass or smartweeds (Polygonum sp.) and a 

 number of other familiar plants. 



CHENOPODIACE.E (Goosefoot Family). Mostly herbs; 

 leaves alternate ; inflorescence in spikes ; flowers small and green- 

 ish ; calyx five-cleft and persistent ; stamens five or less ; ovary 



