ENDOPHYLLUM-LIKE RUSTS OF PORTO RICO 
E. W. Olive and H, H. Whetzel 
The writers recently spent a little over two months in Porto Rico, 
from February 23 to April 26, 191 6, collecting and studying mainly 
the parasitic fungi. A fairly representative lot of rusts were collected 
from many localities about the Island. Among these were five 
aecidioid and one peculiar uredinoid form which, after germination 
studies, we found to be short-cycled and similar to, if not indeed 
identical with, the Endophyllums. 
We wish to acknowledge special obligation to Professor J. C. 
Arthur, not only for determining all our rust collections after our 
return, and for making many suggestions in the preparation of the 
systematic portion of this paper, but also for directing our attention, 
prior to our journey, to certain unsolved problems, in particular to the 
urgent need of clues in the case of the unconnected aecidia of Porto 
Rico. For the preparation of the agar-water medium and for many 
other courtesies we are much indebted to Plant Pathologist E. W. 
Brandes and Director May of the Federal Experiment Station, as 
well as to Dean Garwood, Professor C. E. Hunn and others of the 
Agricultural College at Mayagiiez. For laboratory facilities and for 
other freely tendered assistance we are also under great obligations 
to Mr. J. A. Stevenson, plant pathologist, and to Director Tower, of 
the Insular Experiment Station at Rio Piedras. After our return 
from Porto Rico, most of the hosts of our fungi were determined by 
Director Britton and others of the New York Botanical Garden; 
the grass hosts by Professor Hitchcock and Mrs. Chase; the ferns by 
Miss Slosson, to all of whom we desire to acknowledge our great in- 
debtedness. We wish to express our thanks especially to Mr. Percy 
Wilson of the staff of the New York Botanical Garden, who for several 
days so generously placed his wide knowledge of West Indian plants 
entirely at our disposal. 
Arthur's "Uredinales of Porto Rico, based on collections by F. L. 
Stevens,"^ which proved so very stimulating in our search, enumerates 
10 aecidium-forms, all of which he at that time supposed to be heter- 
^ Mycologia 7: 168-196, 227-255, 315-332. 1915;8:16-33. 1916. 
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