202 



Mycologia 



uring 23-26 by 26-30 fi, wall golden-yellow, 2-3 ^ thick, very finely 

 and sparsely echinulate, the pores being 8 scattered. Puccinia 

 Distichlidis E. & E. was erroneously described as on Distichlis 

 maritima Raf., the host being Spartina gracilis Trin. This rust 

 has urediniospores whach are globoid, measuring 23-26 by 26-30 ju, 

 are golden-yellow with a wall 3-3.5 /a thick, very finely and 

 sparsely echinulate, the pores being 8 scattered. The teliospores 

 of the two rusts possess the close resemblanc of correlated forms. 

 The distribution of the two-celled form extends from Iowa north- 

 west to Wyoming and Montana, and of the one-celled form from 

 Illinois west to Colorado and north to Alberta. The telial hosts 

 of the two forms are the same. Puccinia Distichlidis has been 

 cultured^^ on 21 different aecial hosts without success but not on 

 the aecial host of Uromyces acuminatus. It seems, therefore, 

 extremely probable that its aecial host is on some member of the 

 primrose family, perhaps Steironema, or some member of the 

 phlox family, but more Hkely the former. 



Another evident case of correlation exists between Puccinia 

 Pammellii (Trel.) Arth. and Uromyces graminicola Burr. In 

 1904, Dr. Arthur reported the cultures^^ of Puccinia Panici 

 Diet, as the rust on Panicum virgatum was then called, upon 

 Euphorbia coroUata L. This rust has globoid urediniospores, 

 measuring 19-23 by 21-24 fi, with a light cinnamon-brown wall 

 about 2/x thick, finely verrucose-echinulate, the pores are 3 or 4, 

 usually approximately equatorial, but often scattered. The telio- 

 spores are small, somewhat thickened and rounded above. 



Uromyces graminicola Burr, also on Panicum znrgatum L. has 

 been cultured^^ on 19 various hosts without success but never on 

 Euphorbia to the writer's knowledge. It has globoid uredinio- 

 spores measuring 15-19 by 18-23 ^ which have all their other char- 

 acters identical with those of Puccinia Pammellii. The telio- 

 spores of these forms have the same morphological resemblance 

 which is expected in correlated species. Puccinia Pammellii has 

 a distribution from Pennsylvania west to Nebraska and south to 

 the Gulf of Mexico and Uromyces graminicola has practically the 



Mycologia 2: 219, 1910; 4: 11, 1912. 

 ^®Jour. Myc. 11: 56. 1905. 



^°Jour. Myc. 12: 13. 1906; Mycologia i: 232. 1909; 4: 12. 1912. 



