THE AXGIOSPERMAE : STEMS 



923 



Phloem 



Fig. 905. — Runiex crispus. Transverse section of stem 

 showing vascular bundles with inverted orientation 

 attached to the inner side of the large vascular bundles 

 of the normal ring. 



Secondary xylem 

 Phloem island m ^' * 



Primary phloem 

 Primary xylem 



T^' 





Fig. qob.—Stiaeda fruticosa. Transverse 

 section of stem with secondary thicken- 

 ing showing phloem islands included in 

 the zone of secondary xylem. 



