PAPERS GIVING RUSTS OF NORTH AMERICA. 209 



origin being obscure. The microscope shows no evidence of my- 

 celium, and the spots arc probably not due to a fungus. This con- 

 clusion has been confirmed by Dr. C. L. Shear of Washington, D. C. 



*285i. 41. C. U. Clielidonii. L.v.S., very rare. On leaves of Clielidonium 

 sent from New York. 

 C. spots yellowish. Sori irregular in form, clustered, confluent. 

 Spores ratlicr large, fuscous and black, oval, loosely scattered. 



Represented by an angularly ovate leaf, incised, 3 by 5 cm., hav- 

 ing characteristic white hairs, especially on the veins, mounted, and 

 by an empty packet labelled inside " Uredo ChcUdon'ii Halsey NYk,'^ 

 and outside " Cseoma (Ured) Clielidonii LvS NewYk Halsey." 



The error in mistaking Osmorrhiza for Chclidoniiim was pointed 

 out by Dr. ^^^ G. Farlow in the preface to his " Host Index of 

 Fungi," 1888. 



The mounted fragment of leaf bears two small groups of brown 

 sori on the under surface, rather pulverulent, having both uredinio- 

 spores and teliospores present, identical with Puccinia PimpinellcB 

 (Str.) Mart. (P. Osmorrhizcc C. & P.), and essentially the same as 

 nos. 2829 and 2841. It is a curious result of too credulously ac- 

 cepting the first impression of the identity of a host that led 

 Schweinitz three times to describe the same rust from the same host, 

 as if representing three independent species on three wholly unlike 

 and unrelated hosts. 



4. Albugo. 



Note. — Two numbers are given under this heading, both true 

 representatives of the accepted Phycomycetous genus Albugo, and 

 they are, therefore, omitted here. 



5. Sporidiis incrqualibus (spores unequal). 

 ♦2854. 44- C. U. gyrosum, Lk. 105, on leaves of Rubus Idsus, Betlilehem. 



Represented neither by specimen nor packet. There is, how- 

 ever, an original packet labelled " Caeoma (Ur) gyrosa Reb. in Rub 

 Id. Kunze." and a similar one in the Herb. Curtis at Harvard Uni- 

 versity. This collection shows a few small fragments of raspberry 



