76 



PLANT RELATIONS. 



emerge with 

 great rapidity, 

 and trees be- 

 come covered 

 with new foliage 

 in a few days. 

 From the sub- 

 terranean stems 

 the aerial parts 

 come up so 

 speedily that the 

 surface of the 

 ground seems to 

 be covered suddenly with young vegetation. This sudden 

 change from comparative rest to great activity has been 

 well spoken of as the " awakening" of vegetation. 



Fig. 67. A potato plant, showing the subterranean tubers 

 After Strasburger. 



0. Stems bearing floral leaves. 



54. The flower. — The so-called 

 " flowers " which certain plants 

 produce represent another type of 

 shoot, being stems with peculiar 

 leaves. So attractive are flowers 

 that they have been very much 

 studied ; and this fact has led 

 many people to believe that flowers 

 are the only parts of plants worth 

 studying. Aside from the fact 

 that a great many plants do not 

 produce flowers, even in those 

 that do the flowers are connected 

 with only one of the plant pro- 

 cesses, that of reproduction. 

 Every one knows that flowers are 

 exceedingly variable, and names 



Fig. 68. The rootstock of Solo- 

 mon's seal ; from the under side 

 roots are developed ; and on the 

 upper side are seen the scars 

 which mark the positions of the 

 successive aerial branches which 

 bear the leaves. The advanc- 

 ing tip is protected by scales 

 (forming a bud), and the posi- 

 tions of previous buds are in- 

 dicated by groups of ring-like 

 scars which mark the attach- 

 ment of former scales. Advanc- 

 ing in front and dying behind 

 such a rootstock may give rise 

 to an indefinite succession of 

 aerial plants.— After Gray. 



