THE STEM 



61 



97. A scaly bulb (like that of the Lily, Fig. 51), is one in which 

 the scales are thick but comparatively narrow. 



98. A tunicated or coated bulb is one in which the scales enwrap 

 each other, forming concentric coats or layers, as in Hyacinth and 

 Onion. 



99. Stems as foliage. All green parts of the plant, 

 whether belonging to the leaf or to the stem, serve the 

 same purpose as the foliage to some extent ; for example, 

 the green twigs of a tree and the green stem of an herb. 



52. Flattened leaflike steins of Muhlenbeckia ptoty- 

 clados, bearing flower clusters at the nodes. 



A considerable number of plants have come to dispense 

 with leaves entirely, modified stems doing their work. 

 Thus, in the Asparagus what appear to be needle-like 

 leaves are in reality branches springing from the axils of 

 the true leaves; the leaves themselves being minute, dry 

 scales. In Muhlenbeckia (Fig. 52) the nodes of the stem 



