18 INTRODUCTION'. 



is the case, especially with regard to the two 

 roots above mentioned, as well as the radish and 

 many others. The last-named tuber, and turnip 

 also, are either annuals or biennials according 

 to the time of the year they are sown. 



Perennial flower-roots assume very many dif- 

 ferent habits. By duration, as the anemone, 

 which is propagated by enlargement of the 

 tuber, in which there is an annual subdivision of 

 the crown. The ranunculus is perennial, partly 

 by duration and by offsets. The hyacinth, tulip, 

 &c. are perennial, from containing in their ra- 

 dical plate an interminable series of individuals, 

 which are developed in succession. Fibrous- 

 rooted flowers are perennial by multiplication of 

 their crowns, diverging from the first centre. 



The modes of increase are also various. Dis- 

 tinct tubers are in some instances produced on 

 the lower part of the stem, and just above that 

 of the former year, as crocus, gladiolus, &c. At 

 the lower part, as in some sorts of arum ; — from 

 the body in irregular processes, as anemone ; — 



