22 



THE FLOWERING PLANT. 



members, leaves, which usually differ considerably from it. This, 



among other points, dis- 

 tinguishes the stem from 

 the root. We have also 

 seen that stems often 

 bear adventitious roots 

 (fig. 4), but this is not of 

 primary importance, at 

 least from a morphologi- 

 cal point of view. 



Stem and leaf are so 

 constantly associated that 

 it is impossible to treat 

 of one without reference 

 to the other. A collective 

 name, that of shoot, has 

 therefore been given to 

 the stem with its leaves. 

 The broadest grouping 

 that can be made of plant 

 members divides them 

 into only two sets, viz., 

 roots and shoots. 



The regions of the stem 

 to which leaves are at- 

 tached receive the name 

 of nodes, while the in- 

 tervening portions are 

 known as inter-nodes. 

 Nodes are often thick- 

 ened, and adventitious 

 roots generally arise from 

 them. Where a leaf joins 

 the stem there is an upper 

 angle formed (usually 

 acute), and a lower angle 

 (usually obtuse). The 

 former is known as the 

 axil of the leaf. This 



j. 4.— Diagrammatic Longitudinal Section through a point is mentioned here 

 Young Maize Plant (Zeamais) [from Sachs]. W. pri- ] PM1KP ,-j. ,•„ j-i, p ril lp 

 mary root; </>, <*,', </>", <*»'"• adventitious roots spring- oecailSG ID IS tne lUie 

 ing endogenously from the stem (s) ; b, V, b". older in flowering plants for 

 leaves, cutoff short; b'". young leaves of the terminal , ■, 



lo Thp o-vnwhirr nnints fli'P OianCJl 



bud ; k, k. axillary buds. 



parts left white are fully grown 

 the root are root-caps. 



The growing points are 

 parts grey; 

 The white tip: 



stems to arise 



represented black, the elongating parts grey; the j n leaf-axils (fio-s 2, 4, 



of , . _, j p 



and 35). Such branches, 



