ECOLOGICAL CROSS SECTION OF THE MISSISSIPPI. 



205 



like Aralia quinquejolia, even form the bud, which produces 

 the flowering stalk in June or July, two years earlier. Con- 

 trary to what one would be led to expect, the flowering period 

 is rather late. Trees respond readily to a greater amount of 



DIAGRAM 1. 



SPECIES TLOWERING AND FRUITING, THROUGH SEASON, 



4 

 I 



heat. It is a matter of yearly obseryation that the flower 

 buds of those branches of Acer facing the south open as much 



weeks 



Simi- 



larly, rosettes of biennials and perennials which during the 

 winter have been kept in greenhouses or frames blossom much 



