350 



UREDINEAE. 



Stems, leaf-stalks, and leaf-nervature often undergo one-sided 

 tlnckening and curvature as a result of formation of aecidia. 

 Wakker thus summarizes his observations on the anatomical 

 changes in these malformed parts of Urtica : tliere is an en- 

 largement of cells and an increase in the number of large inter- 

 cellular spaces ; no formation of collenchyma, interfascicular 

 cambium, and chlorophyll ; a diminished formation of calcium 

 oxalate ; an orange coloration of the cell-sap ; and a distension 

 or rupture of the epidermis. 



Fio. ISa.— /"i/.ccmja co/ricis on Stinging Xettle. The aecidial cushions have caused 

 sweUing and distortion of stems and leaf-stalks, also swollen outgrowths on the 

 leaves, (v. Tubeuf phot.) 



Klebahn and Magnus believe that there is a Fuccinia on 

 Carex acuta and G. Goodenoughii related to an Accidium on 

 Rihes Grossidaria, B. rubrum, and B. aure^cm ; also a Fi/ccmia 

 on Garex riparia with an Aecidium on Hibcs nigrum. (_)n this 

 account Klebahn ^ distinguishes Puce, caricis i., ii., and in., 

 agreeing respectively with P. Pringsheimiana Kleb., P. caricis 

 (Sclmiu.), and P. Magiiusii Kleb. 



P. Schoeleriana Plowr. et Magn.^ (lUitain). Uredo- and 

 teleutospores on Gctrcx arenaria ; aecidia on Scnccio Jacohaea. 



'KleV)ahn, ZeMxrJirift f. Pflanzenkrankhdten, 1892, 1894, and 1895. 

 - Iledingia, 188(5. 



