The Structure of Stems 



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Vf >-;. 





Fig. 72. Photograph of a stem tip of coleus, an opposite-leafed herb. The 

 growing point is in the center above, surrounded by two young leaves. Just 

 below are two shoulders representing the second node, the leaves of which are at 

 right angles to the first pair and do not show. The leaves of the third node 

 (partly shown in photograph) are quite large and have growing points in their 

 axils. Note change in form and size of cells as growth proceeds. 



cells which are greatly elongated — the length is many times the 

 breadth. These cells touch the adjoining cells along their sides, 

 but their ends are pointed or wedge-shaped and fit in between the 

 cells above and below them. A tissue composed of this type of 

 cells is called prosenchyma. 



