MORPHOLOGY OF ANGIOSPERMS. 



103 



the Cacti, the leaves being suppressed or considerably reduced. 

 Branches are not infrequently modified to hard, pointed and 

 spiny structures, as in the Japanese quince, when they are spoken 

 of as thorns. Leaves and even flowers may arise upon thorns, 

 which shows that they are modified branches. 



Fig. 67. Plant of spearmint (Mentha spicata) showing procumbent stems or leafy 

 runners from which roots are developed at the nodes, and one erect branch at the left from 

 which a new plant will be developed. 



or 



A number of plants ascend into the air on other plants 

 other objects which serve as supports, either by attaching them- 

 selves to them or by crawling around them, when they are dis- 

 tinguished as twiners and climbers. Twiners ascend by a special 



