DYNAMIC STUDIES OF VEGETATION 



43 



7. Hempstead Plains/ about 3 miles S.S.E. of Westbury. 

 Vegetation mostly Andropogon scoparius, with some lonactis 

 linariifolius and a few other plants, somewhat sparser than the 

 average for this area. October 3. 



7. Hempstead Plains, about a mile S.S.E. of Westbury. 

 Vegetation denser than the average, nearly all Andropogon 

 scoparius, with culms about 3 feet tall. October 27. 



The following table gives the results of the weighings, in 

 pounds per acre: 



1. Upland meadow . . . 



2. Spartina patens . . 



3. Typha latifolia . . . . 



4. Phragmites 



5. Typha angustifolia 



6. Hempstead Plains. 



7. Hempstead Plains . 



495 

 279 

 296 

 1,585 

 843 

 168 

 265 



Probably little significance is to be attached to the weights 

 of the fresh vegetation, especially in the last two, which were 

 cut in October and had evidently lost some of their water 

 before that time. With these exceptions the one showing the 

 highest r^tio of dry to green weight is no. 2, which is a tough 

 dense grass, and lost less than half its weight in drying. No. 4 

 is nearly equal to it in than respect, however. 



In dry weight the Phragmites leads by a large margin. It 

 would be interesting to know if there is any natural vegetation 

 in the world that makes a greater growth per unit area in one 

 season. The same species is very widely distributed, and one 

 might suppose that in a warmer climate it would do still better. 

 A photograph of a nearly pure stand of it at the edge of the Ever- 

 glades was published in the Third Annual Report of the Florida 

 Geological Survey (fig. 28, p. 286), and that is much m.ore open. 

 But the comparison is not quite fair, for that photograph was 

 taken in April. The saw-grass which covers most of the Ever- 

 glades makes a pretty dense growth, but as it is evergreen the 



<^ See Torreys, 12 : 277-287. 1912. 



THE PLANT WORLD, VOL. 21, NO. 2 



