CHAPTER III 



THE STEM 



IN the previous chapter, although attention has mainly 

 been directed to the root, it can scarcely have escaped 

 notice that most of the plants examined are made up of 

 two well-marked and very distinct portions (i) the 

 underground root, and (2) the aboveground stem bear- 

 ing leaves and flowers, and often for convenience spoken 

 of as the " shoot." 



It is true that in some plants for example, the house- 

 leek and primrose the stem is exceedingly short, so that 

 the leaves appear to spring almost directly from the 

 ground. In other cases, for instance, in climbing plants 

 such as the hop, scarlet runner, etc., the stems are very 

 long and thin, and the same holds good for many creep- 

 ing plants like the couch grass. 



Stems also vary greatly in another respect. Whilst 

 young they are almost all soft and green ; some remain 

 permanently in this condition, but others become hard 

 and woody with age. The comparison of young and old 

 shoots of elder, and young and old garden balsams illus- 

 trate this point very well. Putting aside for the moment 

 all these differences, we may say that plants in general 



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