NOTES ON SOME POLEMONIACEOUS 

 RUSTS^ 



C. R. Orton 



Of the many problems encountered in taxonomic work with 

 any group of plants that of nomenclature is sure to require a con- 

 siderable amount of time and often more patience than the worker 

 possesses. There are always some names in question whose iden- 

 tity is not certain because of discrepancies, either with regard to 

 the labelling of type specimens or in connection with the pub- 

 lished descriptions. The situation becomes more acute for the 

 taxonomist working with parasitic organisms. Here the chance 

 of error is practically doubled for both parasite and host are 

 concerned. 



A good example of such a situation has been encountered in 

 the study of several rusts on polemoniaceous hosts. Several stu- 

 dents of the rusts have been puzzled with this particular tangle 

 and some valuable information has come to light. Holway^ pub- 

 lished some notes bearing on these species several years ago but 

 since then few, if any, descriptive notes have appeared. During 

 the preparation of the manuscript on the genus Allodiis the 

 writer^ was compelled to reinvestigate this entire group of rusts 

 with the result that some interesting facts have been disclosed 

 v/hich are thought to be of sufficient importance to record for the 

 benefit of subsequent workers. 



One of the earlier difficulties in connection with this group of 

 rusts was due to the inaccessibility and consequent uncertainty 

 regarding type specimens. During the summer of 1918, through 

 the efiforts of Dr. J. C. Arthur, Prof. H. S. Jackson, and other 

 members of the botanical staff of the Purdue Agricultural Ex- 



1 Joint contribution from the Department of Botany, Indiana Agricultural 

 Experiment Station, and the Department of Botany, The Pennsylvania State 

 College, No. i6. 



2 Holway, E. W. D. Notes on Uredineae, IV. Jour. Myc. ii : 268. 1905. 



3 Orton, C. R. North American Species of Allodus. Mem. N. Y, Bot. 

 Garden 6: 198—200. 1916. 



168 



