AMERICAN UREDINE^E. 183 



and teleutosporic stages, but the uredo stage is of brief 

 duration and rarely collected. Specimens gathered as early 

 as the middle of June in central Indiana show teleutosori. 



In the teleutosporic condition it is difficult to distinguish 

 this species from the preceding. Some search, however, 

 will usually reveal at least a few of the characteristic 

 uredospores, even in collections made in the winter season, 

 and the chief reliance should be placed upon these. The 

 thin-walled echinulate uredospores of P. aiidropogonis are 

 wholly unlike the thick-walled, small, and finely tubercu- 

 late uredospores of P. cllisiana. 



The type specimen of P. aiidropogonis Schw. is in the 

 Schweinitz collection of the Philadelphia Academy of 

 Sciences. It is an ample one, in the original packet, 

 unmounted, and labeled in Schweinitz's handwriting. The 

 sori are very numerous. The host is not named on the 

 packet, but appears to be Audropogon scoparius. The 

 type locality is not given, but it is probably Bethlehem, 

 Pa., as stated in the author's list of N. Am. Fungi (Trans. 

 Am. Phil. Soc. 4:295). We have examined the type and 

 find the characteristic, thin- walled, echinulate uredospores, 

 and no other sort. There can be no question regarding 

 the error of Lagerheim in supposing the Schweinitzian rust 

 to be a thick-walled uredoform rather than a thin-walled 

 one. No other specimen of rust on Audropogon occurs in 

 the Schweinitz collection, unless one include his Cceonia 

 {Uredo) androftogi, a very dissimilar form on Clirysopogon 

 avenaccns {Audropogon of earlier authors) . (See page 177.) 



The specific name Pentastemonis ', which Schweinitz gave 

 to the secidial form a dozen years before he employed the 

 one we have adopted, can not be used, as there is already 

 a Pnccinia pentstemonis given by Peck in 1885, to a rust 

 on Pcntstcmon found in western North America. 



The form of the name as Schweinitz wrote it, was 

 " Puccinia andropogi" but we have followed Schroeter, 

 Saccardo, Kuntze, and many others in writing it P. 



