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PLANT PHYSIOLOGY AND ECOLOGY 



position, and note the time that elapses before it reaches the perpen- 

 dicular. 



Select three plants of Chamcenerium that are beginning to flower. 

 Reverse a flower and leaf of one, fixing the base of the stalk so that the 



Fig. 42. A flowering branch of the fireweed, Chamanerium angustifolium, 

 accidentally broken and inverted. The pedicels are curving to place 

 the flowers and fruits in the usual position. 



blade and flower are free to turn. Turn the other plants upside down, 

 placing one in darkness. Make sketches of the resulting changes, and 

 explain them. 



