148 BOTANICAL GAZETTE [august 



Placing the collections side by side, they were found to look alike, 

 both consisting of a few large leaves well covered with rust. It will be 

 noticed that the published data for the hosts are identical, even to the 

 number, in fact having originally consisted of a single collection, which 

 was separated by the collectors into two parts, one part being distin- 

 guished from the other by adding the letter "a" to the number. The 

 material was handled at the herbarium of the National Museum, and 

 one of the two parts was examined also at the Gray Herbarium. Thus 

 at least three highly trained taxonomists passed upon the identity of 

 the hosts, or rather the host, and the three microscopists of the Purdue 

 Agricultural Experiment Station, who passed upon the identity of the 

 rusts, or rather the rust, did their part without a suspicion of any- 

 thing amiss. It took a seventh man to bring the two descriptions and 

 the sets of material together and point out that only one rust and one 

 host were involved. The two packets of material were subsequently 

 sent to Mr. Paul C. Standley of the National Museum with a state- 

 ment of the situation, and were returned with the information that the 

 host was neither Nicotiana tomentosa nor Acnistiis arbor escens as pub- 

 lished, but was Acnistus aggregatus (R. and P.) Miers. 



It would have been unnecessary to give a detailed account of this 

 series of errors had the duplicate names of the rust in their fortuitous 

 position on the page been reversed. The American Code of Nomencla- 

 ture recognizes page position in deciding priority. In this case, how- 

 ever, it may be assumed that duplicate names having been given 

 simultaneously to the same fungus, or as near as it is possible to do so 

 in print, one of them correctly formed and the other glaringly erroneous, 

 the correct name should be maintained and the other treated as a 

 blunder and discarded. This disposition of the case is also in accord 

 with the International Rules of Nomenclature, which give to the author 

 the privilege of choosing between two names of the same date, which 

 subsequently he considers to be conspecific (Article 46). The correct 

 name to include both descriptions, as well as other data, therefore, is 

 Puccinia Acnisti Arth., on Acnistus aggregatus. Of course this instance 

 has no bearing upon such inappropriate but tenable names as Puccinia 

 Distichlidis , at first supposed to be a rust on Distichlis spicata, but 

 years later found to be on Spartina gracilis, or as P. Sorghi, now known 

 never to occur on Sorghum. 



The same species of fungus, to which this note refers, has been listed 

 in the account of the Uredinales of Costa Rica, where it is correctly 

 given as Puccinia Acnisti, and in this case is on Acnistus arbor escens 

 (Mycologia 10:138). — J. C. Arthur, Purdue University, Lafayette, I nd. 



