20 



Mycologia 



densis, Arnica sp., Boltonia asteroides, Laciniaria scariosa, Sym- 

 phoricarpos racemosus, and Hydrophyllum virginicum. 



Still another collection of what appears to be the same species 

 of rust was collected on Koeleria cristata (L.) Pers., by Miss 

 Louise M. Falk, at Boulder Colo., and sown April 27, on Senecio 

 higens, Grindelia squarrosa, Symphoricarpos racemosus, Hydro- 

 phyllum virginicum, and Arabis Holhoellii, with infection only on 

 the first, which showed pycnia May 14, and aecia May 19. 



The aecia on the several hosts, thus produced, correspond in 

 structure, and are peculiar in having evanescent peridia, the spores 

 being retained by the surrounding tissues of the hypertrophied 

 leaf. The striking appearance of the aecial groups suggested one 

 of the early synonyms: Aecidiuni sclerothecioides Ellis & Ev. 

 These cultures, although still lacking in completeness, have 

 enabled us to bring together a number of uncertain forms with 

 a considerable degree of assurance, and to extend both aecial and 

 telial hosts. 



19. PucciNiA ARGENTATA (Schultz) Wiut. At my request 

 Professor Guy West Wilson, of Fayette, Iowa, made a somewhat 

 trying excursion to Decorah, Iowa, and with the aid of directions 

 supplied by Professor E. W. D. Holway, who resided there for 

 many years, obtained living plants of Adoxa Moschatellina L., 

 l)earing aecia, which were potted and thrived. Two sowings 

 were made April 18, by suspending the plants of Adoxa bearing 

 aecia over plants of Imp aliens aurea. In both instances a great 

 abundance of urediniospores began to appear May 2. Again on 

 April 21, two more similar sowings were made on other plants of 

 Impatiens, and an equal abundance of urediniospores appeared 

 May 3. These were followed on all four plants by an unusual 

 abundance of teliospores, the record being made June 6, although 

 they first appeared somewhat earher. 



The aecia on Adoxa, which are of limited distribution in Amer- 

 ica, early attracted the writer's attention, and as early as 1883^^ 

 a first attempt was made toward solving their life history. Since 

 the cultures of Bubak^* proved that the European form on Adoxa 

 was the aecial stage of telia on Impatiens, I have attempted to 



3^Bot. Gaz. 10: 369. 1885. 

 Centr. Bakt. lO^ : 574. 1903. 



