ECOLOGICAL CROSS SECTION OF THE MISSISSIPPI. 215 



when 



ymbols it has bee 



of 



This depends not only on the 



but also on the ecological relations^ especially the degree of 

 development of others associated with it. The seasons are 

 indicated as follows: | spring, + spring and summer, — sum- 

 mer, H- spring, summer, autumn, X summer and autumn, 

 autumn, * spring, summer, autumn, winter. Where the 

 symbol J accompanies any of the above it indicates that the 

 plant forms a striking feature of the winter aspect. The 

 symbol f accompanying any of the above indicates that the 

 plant has two flowering periods. The latter will be found 



bearing 



months. Thus Fl, Je, Jl indicates 



and Julv. Where 



separated by 



from 



the presence of the symbol t in other columns. The same 

 applies to the fruiting periods indicated on the odd numbered 

 pages. As fruiting period is recognized the time when the 

 fruit is ripe or almost so and sufficiently advanced to form a 

 representative herbarium specimen. In cases where the 

 fruit stays on throughout the winter this is indicated by giv- 

 ing the last month of fruiting as December. For convenience 

 in correlating the data on opposite pages the species have been 

 numbered consecutively, the numbers being repeated on each 

 page. 



As shown by the tables and accompanying diagrams 1 to 

 6, even in May a considerable proportion of the local species 



is in flower. 



months 



maintained with but slight fluctuation. In view of the fact 



marked increase in the number of Compos 

 ig August and September it is evident tl 



must 



be a decrease in other families. This is clearly shown 

 by the diagrams. While the Ranunculaceae and Rosaceae 

 decrease in numbers, the Compositae increase. It is also 



eraceae 



Gramineae do so only in August. July and August 

 neatest number of soecies in flower. 



