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Fig. 7-6. Diagram of the primary vascular strands in 

 the stem of Linum perenne. The numbers from 21 

 (above) to 49 (below) mark the positions of leaves in 

 the generative spiral, indicated by a thin line. The 

 bundles are shown by heavy lines for those on the 

 nearer surface and by dotted ones for those behind. 

 Various helices, in Plantefol's terminology, may be dis- 

 tinguished, such as 30-33-36, 28-33-38, and 25-33-41. 

 There seems no certain way to determine which are 

 the "true" ones. ( From Esau. ) 



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