GENERAL MOEPHOLOGY OF THE PLANT 37 



Adventitious shoots sometimes arise from roots, as may be 

 observed ia many Rosaceae, the Moutan Pteony, the Japan 

 Anemone, and many other plants. They may in many cases be 

 artificially stimulated to appear ; if the root be wounded, it will 

 often produce them, much in the same way as the leaves of 

 Begonia. The Blackberry under such circumstances will pro- 

 duce shoots from its roots, so freely indeed that the plant can be 

 propagated by root- cuttings. 



Fig. 50. 



Fig. 51. 



Fig. 52. 



Fuj. 50. Climbing stem of the 

 l7y. fl, a. Aerial roots. 



Fig. 52. Twining stem of a 

 species of Convoloitlu.s. 



Fig. 51. Twining stem of Honeysuclde. 



Forms of Stem axd Branchi-.s. — The stem is usually more 

 or less cylindrical, though this is far from universal. In many 

 herbaceous plants it becomes angular, and in some, particularly 

 in those of certain natural orders, as the Oactacese, Orohidaceie, 

 Euphorbiacese, &c., it assumes a variety of anomalous forms. 

 Thus in many epiphytic Orchids it becomes more or less 

 oval or rounded, and has received the name of pseudohulh 

 {fig. 33, h, h) ; in the Melon-cactus it is globular; and in other 

 Cacti it is columnar, more or less flattened, or jointed. In the 



