VOLUME LXIII 



NUMBER 2 



THE 



Botanical Gazette 



FEBRUARY 1917 



A comparative study of winter and summer 



LEAVES OF VARIOUS HERBS 



CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 224 



I 



J. P. Stober 



Introduction 



The structure of most plants varies with the habitat and even 

 with the varying conditions of the same habitat. This has been 

 emphasized by Grevillius, 1 Chermezon, 2 Cowles, 1 Starr, 4 

 and others. Grevillius made an extensive comparative study of 

 vegetation growing on the island Oland. He compared the plants 

 of a dry, rocky, treeless plain (alvar) with the same species growing 

 *n favorable regions. The former he calls alvar forms; the latter, 

 normal forms. The alvar forms, in general, were more hairy and 

 had a more highly cutinized and thicker epidermal wall, a more 

 compact palisade parenchyma, and more closely crowded stomata 

 than the normal forms. 



These structural peculiarities due to environmental changes 

 may be observed readily in almost any plastic plant. Oenothera 



1 Grevillius, A. Y., Morphologisch-anatomische Studien iiber die xerophile 

 Phanerogamen vegetation der Insel Oland. Bot. Jahrb. 23:24 108. 1897. 



2 Chermezon, H., Recherches anatomiques sur les plantes littorales. Ann. Sci. 

 Nat. Bot. 12:117-313. 1910. 



* Cowles, H. C, The ecological relation of the vegetation of the sand dunes of 

 Lake Michigan. Bot. Gaz. 27:95-117, 167-202, 281-308, 3 6 *-39 r - l8 99- 



4 Starr, Anna M., Comparative anatomy of dune plants. Bot. Gaz. 54: 

 26 5"-3°5- JO 12 - 



89 



