UREDINALES OF PORTO RICO BASED ON 

 COLLECTIONS BY H. H. WHETZEL 

 AND E. W. OLIVE 



J. C. Arthur 



A botanical expedition was made to Porto Rico in the spring 

 of 1916 by Professor H. H. Whetzel, of Cornell University, and 

 Dr. E. W. Olive, of the Brooklyn Botanic Garden. They reached 

 the island on February 23, and left it on April 26, permitting 

 thus about two months of uninterrupted work. All kinds of 

 plants were collected, but especial attention was given to fungi, 

 and a generous portion to the Uredinales. As a result of their 

 labors 383 numbered collections of Uredinales were secured and 

 shortly afterward submitted to the writer for study. The 383 

 collections were found to represent 122 species, as now under- 

 stood, and these are systematically treated in the following pages. 

 The writer and the scientific public are under large obligation to 

 the collectors for their assiduous and painstaking labors, and for 

 their generosity in turning over to another the whole set for un- 

 reserved examination and record. 



A unique and most fruitful part of the work of the collectors 

 was a careful and adequate test of the mode of germination of 

 all so-called species of Aecidium, made at the time they were 

 found. The new methods of testing the behavior of spores on 

 solid substrata or on water surfaces were used. From the results 

 it was learned that four forms, heretofore considered aecia and 

 supposed to belong to heteroecious species, and another similar 

 form but unrecorded for the island, were in reality aecidioid telia 

 representing short cycle species, while five other similar forms 

 were undoubtedly to be considered heteroecious aecia. The full 

 morphological and incidentally taxonomic study pertaining to this 

 part of the subject has been published by the collectors (Am. 

 Jour. Bot. 4: 44. 1917). 



In connection with observations on the aecia-like species care- 



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