THE STEM. 



33 



where axillary buds are produced at the base of the dying flowering 

 stem in autumn, and grow up above ground at once to. form leafy tufts, 

 lasting through the winter, and giving birth to flowering stems in the 

 next season. 



Offsets, Runners, etc. The leafy shoots of perennial plants, 

 with their axis and adventitious roots, may be separated artificially, 

 and used for propagating the plant (gardeners call this " parting 

 the roots") ; and certain plants are naturally multiplied in the 

 same way, by buds or branches which have received special names. 

 Thus the herbaceous flowering stems of the House-leeks (Semper- 

 vivum), after flowering, produce buds in the axils of their lower 

 leaves which expand into leafy rosettes. The parent stem dying 

 down, these are thrown off as detached plants, and strike root ; in 

 the following season they send up a flowering stalk and repeat the 

 process. The separating tuft formed in the autumn is called an 

 offset or stolon. The Strawberry-plant in like manner produces, in 

 the axils of its leaves, buds which in the same season expand 

 several of their internodes, and form long filiform branches, the 

 buds of which give rise to rosettes of leaves, and strike root, and 



Etraw berry-plant with runners. 



thus form independent plants : such shoots are called runners 

 (fig. 26). In all these cases the herbaceous flowering stem is of 

 two years' growth, its branching portion belonging to the autumn, 

 the ascending flowering portion to the succeeding spring or 



summer. 



Special names have been given to certain forms of the herbaceous stems, 

 some of which are not very definite. Botanists sometimes call the stem 

 of Grasses a culm. 



