BOTANY FOR BEGINNERS 



CHAP. 



The Wallflower is covered with spindle-shaped hairs, and 

 upon the Stock branched hairs are found. 



In the Stinging Nettle large hairs for protection are found. 

 When the tip of such a hair enters the finger it breaks off and a 

 fluid is injected into the wound causing a well-known 

 smarting sensation. 



The surface of a stem may be covered with prickly structures, 

 which may be produced by the modification of hairs, or other 

 structures. The hooks on the stems of the Hop, Cleavers, arid 



Borage are true 

 hair-structures, be- 

 cause they are de- 

 veloped from the 

 surface layer of the 

 plant. The struc- 

 tures found on the 

 stem of the Sloe, 

 and which are 

 fo rm ed from 

 branches which 

 have undergone 

 change so as to 

 protect the plant 

 from its enemies, 

 are called thorns. 

 The prickles of 

 the Hawthorn are 

 modified leaves ; 

 they are, as a rule, 

 termed spines. The 

 prickles of the 



Bramble and Rose are formed not only by the development 

 of the surface covering of the plant, but also by a deeper layer 

 which takes part in their formation. The name emergences 

 may be given to them. 



EXPT. 23. Cut across the stems of the following so as to show 

 their shape : Wallflower (old stem), and flower stems of the Daffodil, 

 Lily, Deadnettle, and Mignonette. Compare their shapes and notice if 

 the stems are solid or hollow. 



EXPT. 24. Examine as many stems as possible to see if they are 



FIG. 33. Spines on the Hawthorn. 



