44 



STUDIES IN THE VEGETATION OF THE STATE 



Lobelia syphilitica 

 Lobelia syphilitica, 

 Sium cicutifolium. 

 Slum cicutifoliuin. 

 Sagittai-ia latifolia. 

 Sagittaria latifolia. 

 Average 



DET TO MOIST SOIL 



J2 S 



5.7 

 30 

 6.0 

 7.0 

 80 

 6.0 

 6.1 





7.7 

 10.3 



8.2 



8.8 

 13.2 

 11.0 



9.7 



bo 



g 

 Q 



U 



68.1 

 52.0 

 36 

 514 

 52.3 

 46.0 

 50.9 



VERY WET SOIL 





12.0 

 13 

 16 

 15 

 14.0 

 31.0 

 15.0 



c3 u 



g^ 



11.4 

 11.5 



8.5 



9.0 



21.4 



14 4 



12.7 



be 





57.9 

 44.0 

 55.5 

 45.8 

 45.3 

 35.0 

 47.3 



Of the plants in the foregoing table, those in the wet soil 

 were by far the more vigorous, since this is their natural 

 substratum. Those in the dry soil had adapted themselves 

 partially to the conditions by reducing the size of their 

 leaves, and increasing the relative amount of their root 

 systems. Sagittaria, being nearer a true hydrophyte, 

 varied the most. All plants showed more or less adaptation 

 to the dryer conditions. The striking difference of 30 per 

 cent in the limit of available water shows to what extent this 

 adaptation had taken place. 



5. 

 Soils. 



The Effect of Decreased Light on Non-available Water in 



Plants were grown in the shade in wet soil in the plot 

 designated as P-I in the planthouse, and in dry soil in plot 

 P-II in the same locality. The average maximum light of 

 these plots was only 1.5 per cent of the standard at noon 

 June 22. Another shade plot was that of Case II in the lab- 

 oratory. This had a maximum average of only 0.5 per cent 

 but the average for the whole period of daylight was only 

 about one tenth of the light in the shade plots in the plant- 

 house. 



