CHAPTER III 

 STEMS, BULBS AND BUDS 



THE stem may be defined as that part or organ of the plant 

 which serves to connect the root and leaves, two sets of organs 

 with very different relationships and functions. In the woody 

 plants, the fibro-vascular system predominates in the stems, but 

 in the herbaceous plants the parenchyma and collenchyma tissues 

 are more abundant. The stem of the woody plant also has a 

 more or less highly developed covering of bark, while the stem 

 of the herbaceous plant has a comparatively simple epi- 

 dermal covering. 



Types of Stems. There are many different types of stems, 

 some of which are so different from the most common form that 



Flo. 8. Stem with buds arranged alternately. 



many people fail to recognize them as stems. Most stems are 

 made up of nodes and internodes ; the nodes marking the points 

 from, which the leaves and most new buds are produced. The 

 leaves and buds are usually arranged alternately (Fig. 8), "oppo- 

 site (Fig. 9') or in whorls. In some few cases there is a single 

 bud which is at the apex of the stem, as in palms and in some 

 of the grasses and sedges. Some of the most common types of 

 stems are as follows: (1) the elongated stem or woody type 

 (Figs. 8 and 9), which is characteristic of our trees and firmer 

 herbaceous plants. These stems are usually erect and present 



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