AMERICAN UREDINE^E. 175 



cultures. It is assumed in the first place that what were 

 described originally as uredospores of this 

 species are true amphispores. We use the 

 name recently proposed by Carleton 

 (Science 13:250) to designate a form of 

 spore having definite physiological and 

 morphological characters, intermediate in 

 most respects between uredo and teleuto- 



Fig. 1. . 



uredo pallida spore, to which the uncertain term, meso- 

 fonJ^ZX spore, has heretofore been applied. In the 

 of Mexico, oct. i, specimens (35a) published with the present 

 fascicle of exsiccates, the amphispores and 

 teleutospores are well shown. In a specimen collected by 

 Mr. Holway at Tizapan, near City of Mexico, Sept. 27, 

 1899 (No. 3504), the true uredospores {Uredo pallida D. 

 & H.) and the amphispores are in similar manner associa- 

 ted. Other specimens in our possession show only one 

 form of spore in each case. The specimens in this 

 distribution are part of the type collection, and show 

 amphispores and in some cases teleutospores. 



36. Puccinia polysora Und . (1897. Bull. Torr. Bot. 

 Club. 24:86). 



36a. On Tripsacum dactyloides L. II. Cuernavaca, Mex., Holway. 



Orig. Desc. "II, III. Amphigenous: sori very small, short, very 

 numerous but irregularly scattered, remaining long enclosed by 

 the tough epidermis of the host, at length rupturing by a narrow 

 slit: uredospores large, broadly oval, 35x30//, scarcely echinulate, 

 the epispore of medium thickness, pale rusty-brown: teleutospores 

 variable, usually short, irregularly oblong, often somewhat con- 

 stricted at the septum, averaging 25X40//, the cells often irregu- 

 larly angled, the upper usually broader than long, blunt or rounded 

 above; apex not thickened; pedicel short." 



The gross appearance of this species is similar to that 

 of the preceding, except that the sori are smaller, longer 



