PAPERS GIVING RUSTS OF NORTH AMERICA. 197 



C. spots obscure. Sori clustered, naked, pulvinate, flavo-rubrous, at 

 first rather solid, finally sprinkled with the minute orange red 

 spores. 



Represented by parts of two small, lanceolate leaves. The 

 smaller one, about 4 cm. long, is mounted, and is doubtless Hclian- 

 thiis giganteiis L. The other, about 7 cm. long, is half in the orig- 

 inal packet, which is labelled " Caeoma (Ured) Hclianthi LvS in 

 Helianth gigant. Bet," and half mounted. It is possibly H. strnmo- 

 sus L. A similar leaf, 4 cm. long by i cm. broad, and evidently 

 part of the latter collection, is in the Michener Collection at Wash- 

 ington, now belonging to the U. S. Department of Agriculture. 



The leaves all show many telia and a fev/ uredinia, of what is 

 now called Coleosporium Helianthi (Schw.) Arth. It is not an 

 abundant species, but is widespread. 



*2829. 19. C. U. Anemonis, L.v.S., on under surface of [leaves of] Anemone 

 quinquefolia, Bethlehem, rare. 

 C. spots yellowish, rather large, sori roundish, dilated, slightly ele- 

 vated, spores pale. 



Represented by a compound trifoliate leaf about 4 cm. broad 

 and long, mounted, having plenty of pale round uredinial sori be- 

 neath. The original packet is labelled inside " Uredo anemones," 

 and in another place " Caeoma Anemonis quinquefolicc Bethl," while 

 outside it reads " Caeoma (Ur) Anemonis quinquefo LvS Detwyler 

 Bethl H." 



As no such rust has been collected since on the host named, there 

 has been much speculation regarding its identity. Not until the 

 senior author's recent visit to examine the Schweinitz material at 

 the Philadelphia Academy did the solution of the enigma become 

 evident. It was then noticed that this so-called Anemone leaf is 

 sparsely sprinkled with long colorless hairs, which remind one of 

 those on Osmorrhiza. Comparing this leaf with material for no. 

 2841 and no. 2851, which had previously been determined as Os- 

 morrhisa, left no doubt that all were the same host. On this host 

 occurs Piiccinia Pimpinellce (Str.) Mart. (P. Osmorrhisce C. & P.), 

 with the uredinia of which" this material exactly agrees. 



This instance illustrates the danger in collecting too small speci- 



