310 



Mycologia 



on Vagnera (Smilacina) steliata, Polygonatum biflorum and Stei- 

 ronema ciliatum, with infection only on the first two, giving 

 pycnia May 18, and aecia May 25, both in the greatest abundance 

 and vigor. Another sowing was made May 19 on Polygonatum 

 biflorum, showing pycnia May 28 and aecia June 7, also on P. 

 commutatum, showing pycnia May 27 and aecia June 6, and 

 furthermore on the following which were not infected: Uvularia 

 grandi flora, Maianthemum canadense, Vagnera racemosa, Iris 

 versicolor and Trillium recurvatum. Still another sowing was 

 made May 23 on Steironema lanceolatum without infection, and 

 May 29 on U. grandi flora, M. canadense, V. racemosa and V. 

 steliata, with infection only on the last, only pycnia showing June 

 6, doubtless owing to the lateness of the season. 



Upon studying the microscopic characters of the material here 

 recorded the form is seen to readily fall into the species given in 

 the North American Flora (7: 231) as Nigredo Polemonii (Peck) 

 Arth. The aeciospores on Vagnera and Polygonatum are much 

 larger (18-29 by 19-35 ft) than those on the same hosts which 

 have been assigned to Puccinia Majanthae (Schum.) Arth. (15-21 

 by 16-27 fi), and have thicker walls, being characters by which 

 the two species may be separated. A collection on Vagnera 

 steliata from the valley of the Teton in northern Montana was 

 some years ago made a new species under the name of Aecidium 

 magnatum Arth., on these same characters. The aeciospores are 

 somewhat larger than those on the other races of the Uromyces 

 on Spartina,. although there is a gradation in size within certain 

 limits for the four races. In fact the four races of this species 

 exhibit not only physiological specialization, but a certain amount 

 of morphological differentiation of both aecia and telia, together 

 with considerable geographical segregation. 



For convenience in discussion of these races there would be 

 some advantage to have distinctive names. The following out- 

 line will fairly well show the present morphologico-physiological 

 divisions with geographical distribution, and corresponding names. 



Uromyces Polemonii (Peck) Barth. (Nigredo Polemonii Arth.) 



Aeciospores 14-19 by 15-23 fi, on Caryophyllaceae. 

 Teliospores generally broad and rounded above. 



