WATER REQUIREMENT AND ADAPTATION IN 



EQUISETUM 



LOUISE DOSDALL 



University of Minnesota, Minneapolis, Minn. 



(Continued) 



III. EXPERIMENTAL RESULTS 



General Outline of Experiments. 



(1) Water content of the soil. 



(a) Maximum and Minimum. 



(b) Wilting coefficient of 



Equisetum fluviatile 

 Equisetum hyemale 

 Ranunculus sceleratus 



(c) Time of wilting 



(1) Equisetum fluviatile and Helianthus annuus 

 Equisetum fluviatile and Phaseolus vulgaris 



(2) Equisetum hyemale and Helianthus annuus 

 Equisetum hyemale and Phaseolus vulgaris 



(3) Equisetum arvense and Helianthus annuus 

 Equisetum arvense and Phaseolus vulgaris 



(2) Water loss by the plant 



(a) Relation of transpiration to plant functions 



(b) Comparative transpiration 



Equisetum fluviatile 



Equisetum hyemale 



Xerophyte: Bryophyllum calycinum 



Mesophyte: Helianthus, Phaseolus vulgaris 



Hydrophyte: Ranunculus sceleratus 



(c) Guttation. 



(3) Transpiration and photosynthesis 



(4) Physiological responses 



(a) Growth and soil-water content 



(b) Growth and light intensity 



(c) Transpiration of soil-water content 



(d) Stomatal behavior 



(5) Adaptations. 



29 



THE PLANT WORLD, VOL. 22, NO. 2 

 FEBRUARY. 1319 



