276 Varietäten etc. — Physiologie, 



Verf. gelangt auf Grund von eingehenden Untersuchungen zu der 

 Auffassung, dass viele Merkmale die hybride Natur dieser Pflanze 

 und deren Mittelstellung zwischen 5. procumbens und 5. saginoides 

 anzuzeigen scheinen, dass aber andererseits verschiedene Charak- 

 tere vorhanden sind, die auf eine distinkte Art hinweisen. In ihrer 

 ganzen geographischen Verbreitung betrachtet, enthält 5. media 

 Brügger vielleicht ungleichwertige, obwohl äusserlich identische 

 Formen. 



Zum Schluss teilt Verf. eine lateinische Diagnose sowie die 

 geographische Verbreitung der S. inedia {procumbens X sagüioides) 

 mit. Abgebildet werden Pflanzen und Blüten von dieser sowie von 

 5. saginoides. Grevillius (Kempen a. Rh.). 



Vries, H. de, The probable origin of Oenothera Lamarckiana 

 Ser. (Bot. Gaz. LVIl. p. 345—361. pl. 17—19. May 1914.) 



It is concluded that 0. Lamarckiana, as represented in the 

 herbaria of Lamarck, Pourret and Michaux was the same plant 

 a Century ago as now; it has been a component of the flora of the 

 eastern United States, and is now a component of the English 

 flora; and the strain now cultivated, introduced into the trade about 

 the middle of the last Century, was probabl}' from some wild En- 

 glish locality, itself possibly stocked from seeds derived from an 

 introduction through Michaux or some other botanist ofhis period. 



Trelease. 



Mac Dougal, T. D., The auto-thermal Integration of clima- 

 tic complexes. (Amer. Journ. Bot. I. p. 186—193. Apr. 1914.) 



After a review of his own and other workers in regard to the 

 relation of temperature to the plant organism, the autor using the 

 wheat plant as an index uses in modified form a method proposed 

 in 1900. It consists in estimating the area of thermographic dia- 

 gram by the line of freezing point and by the temperature tracing 

 from the beginning of a season until a plant had attained a certain 

 stage of its development. The vertical component in such figures 

 being degrees of temperature, and the horizontal element being 

 elapsed time, the resulting accounts are designated as hour-de- 

 grees. The experimental results are tabulated. Harshberger. 



Shive, J. W. and B. E, Livingston. The relation of atmo- 

 spheric evaporating power to soil moisture content at 

 permanent wilting in plants. (The Plant World. XVII, p. 

 81—121. April 1914.) 



The experiments detailed in this paper and tabulated lead first 

 to the substantiation of the general principle, already established 

 by Caldwell, that the amount of water left in any given soil at 

 permanent wilting of plants rooted therein is a function of the in- 

 tensity of atmospheric evaporating power for the period during 

 which permanent wilting is obtained. The studies of the writers 

 have established a ränge of atmospheric evaporation intensities. 

 The authors believe that the discrepancy between the conclusions 

 of Briggs and Shantz and their own may lie in some internal 

 difference between plants grown in summer at Tucson and those 

 in the Washington Greenhouse. Details, as to the quantitatve 



