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A TEXTBOOK OF THEORETICAL BOTANY 



vertical bands of stomata corresponding in number to the number of the 

 vascular bundles. It is doubtful, however, to what extent carbon assimilation 

 is effected by these assimilatory zones, for the plant depends chiefly on the 

 green tissue in the stems. 



Sporangiophore 



Peltate head 



Sporangium 



Nodal septum 

 Annulus 



Fig. 635. — EqiiisetuDi arvense. Longitudinal 

 section of the strobilus showing whorled 

 sporangiophores with attached sporangia. 

 The centre of the axis is fistulose and 

 hollow except for a septum at the basal 

 node. 



Anatomy of the Root 



The roots are produced from the lateral buds, each developing one root 

 at its base. In the rhizome they develop whether the bud grows or not, 



