Pflanzenkrankheiten. — Floris,tik etc. 363 



vermutet einen Zusammenhang mit einer i/e/aw/)5c»r<7^ die auf einer 

 in der Nähe stehenden Populus trichocarpa vorkommt. 



Man wird ihm, falls es noch nicht benannt ist, den Namen 

 Caeoma Pseiidotsiigae Dottglasii (und später den Namen Melampsora 

 Pseudotsiigae unter Beifügung der zweiten Wirtspflanze) wohl geben 

 müssen und die erstgenannte Uredinee als Uredo Chamaecyparidis 

 niitkaensis einstweilen bezeichnen. Losch (Hohenheim). 



Bailey, V., The wild cotton plant ( Thurberia thespesioides) i n 

 Arizona. (Bull. Torr. Bot. Club. XU. p. 301—306. May 1914.) 



The author describes in detail the distribution of the wild 

 cotton plant in the mountains of Arizona in connection with the 

 native cotton boUweevil Anfhonomiis grandis Thurheriae, which it 

 harbors. The plants associated with it are enumerated and the 

 ränge of the plant in altitude is given for the different mountains, 

 such as the Santa Catalina and Santa Rita, visited. 



Harshberger. 



Bartlett, H. H., An account of the cruciate-flowered 

 Oenotheras of the subgenus Onagvn. (Amer. Journ. Bot. I. 

 226-243. f. 1—2. pl. 19-21. May 1914.) ' 



A key is given to O. cruciata, 0. venosa, O. atrovirens, O. bien- 

 nis and its var. leptonieres and O. stenouieres. As new names are 

 published Oenothera stenopetala lasiopetala Barth, 0. atrovirens ShuU 

 & Bart]., O. venosa Shull & Barth, O. biennis leptonieres Barth and 

 0. stenonieres Barth Trelease. 



Cocks, R. S., Notes on the flora of Louisiana. I. (The Plant 

 World. XVII. p. 186—191. June 1914.) 



The object of these notes upon the flora of Louisiana is to 

 record various observations made b}' Cocks during the past few 

 years upon the distribution and occurrence of such plants, as seem 

 worth\' of special notice, whether on account of their rarity, or 

 because their presence in Louisiana would seem to be remarkable. 



Harshberger. 



Douglass, A. E., A method ofestimating rainfall by the 

 growth of trees. (Bull. Amer. Geogr. Soc. XLVL p. 321 — 335. 

 1914.) 



The author undertook to prepare a curve of tree growth, using 

 Piniis ponderosa, as it grows on the great northern plateau of 

 Arizona, as the object of measurement; secondly, to find if there 

 exists any connection between this growth and precipitation; thirdly, 

 to carry this back through long periods to find whether meteorologic 

 variations, if discovered, show association with astronomic pheno- 

 mena. The work was divided into the collection and measurement 

 of sections, the dating of the rings, the yearly Identification of 

 the rings, the time of year of ring formation. Throughout the results 

 are figured graphically and tests of accuracy are applied. Climatic 

 cycles of 33-year and larger variations, a 21-year period and a 11- 

 year cycle were deiermined. The U-year cycle of tree growth esti- 

 mated for a period of 500 years shows close correlation with a sun 

 spot frequency of 11.4 years, so that Douglass has found a con- 



