Sept. 1907] Cidtures of Uredmcae in igo6 195- 



a hundred feet of my laboratory door, and much attention has 

 been bestowed upon it. The first clue to its connection was 

 found on the last day of April of this year, when in company 

 with Mr. F. D. Kern, the writer detected at Fair Oaks, Ind., 

 a hundred miles north of this place, in two well separated spots, 

 some plants of Lactnca canadensis thickly covered with aecia, 

 and intermixed with the affected leaves some leaves of a small, 

 narrow leaved Carex, bearing teliospores of the previous year's 

 growth. No evidence of fruiting could be found on the Carex, 

 and roots brought back and grown in pots have shown no signs 

 of fruit, so that the Carex has not been specifically determined. 

 TeHosporic material was obtained from both localities, and May 

 2 one was sown on Lactnca canadensis and Onagra biennis, the 

 other on L. virosa and two plants of L. canadensis. Onagra 

 showed no infection, but all plants of Lactuca gave rise to pycnia 

 May 9, and aecia May 15, in great abundance. Another sowing 

 was made May 14 on L. sativa, which gave pycnia May 14, and 

 aecia May 28, with ample development. 



This rust is taken to be the same as the one which Dr. 

 Fr. Bubak studied in Bohemia by means of cultures, and which 

 he has very fully described. ^^ No Bohemian collections, however, 

 are at hand with which to make comparison, but two European 

 collections of aecia (Sydow, Uredineen 334 and iioo) show 

 essential morphological agreement with American aecia on Lac- 

 tuca. Dr. Bubak (1. c.) has stated that to him the American 

 and European collections appear distinct, but without saying 

 wherein the difference may lie. To me the differences appear 

 to be habitual. On thin leaved hosts both pycnia and aecia are 

 in more open and indefinite groups. On hosts from the western 

 prairies, which have firm and strongly developed leaves the 

 groups of aecia are usually compact and circumscribed, and sur- 

 round the often amphigenous pycnia. The European aecia be- 

 longing to the species are known under the name Accidium lac- 

 tuciniim Lagherh. & Lindr. 



4. PucciNiA Sambuci (Schw.) Arth. — Teliosporic mate- 

 rial on Carex Frankii Kunth, brought from Frankfort, Ind., by 

 Mr. F. D. Kern, was sown May 10 on Sambncus canadensis, 

 giving numerous pycnia May 16, and abundance of aecia May 

 26. This adds another host to this common species, those already 

 known being Carex trichocarpa, C. lurida, and C. Inpulina}- 



5. PucciNiA Peckii (DeT.) Kellerm. — Teliosporic mate- 

 rial on Carex trichocarpa Muhl., brought from Fair Oaks, Ind., 

 was sown on Onagra biennis May 4, and gave rise to pycnia 

 May 14, and to aecia May 17, both in abundance. Another 

 collection on C. lanuginosa Michx., sent by Rev. J. M. Bates 



^^Centr. Bakt. 9^:924. 1902. 



"See Bot. Gaz. 35:U. 190-3; Jour. Myc. <?:55. 1902; I2:U. 1906. 



