Vegetative Organs of Vascular Plants 125 





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Fig. 13.2-Root tip meristems and histogens. a, b, Zea mays: c, Melilotus alba: d. 

 Lotus tenuis, chromosome complement, iion-hematoxvlin. 



A good dicotyledonous stem growing point can be obtained from 

 young seedlings of Lima beans, kidney beans, soybeans, flax and peas, 

 sprouted in sphagnum or sand. Lima and kidney beans have a large 

 epicotyl of simple structure at the postdormant stage, after the seed 

 coat has been ruptured but the plumule has not yet emerged. Peel off 

 the seed coat, separate the cotyledons, and remove the epicotyl and 

 radicle (Fig. 13.1 5, C) . Good fixation can be obtained with Graf II 



