MAXu.N — STUDIES OF TROPICAL AMERICAN PERNS. 4V-" 



minute diagnostic characters are noted upon painstaking study. Too 

 few trustworthy modern data arc available in published form to 

 permit of more than general deductions as to geographic distribution. 

 The problem often is, at present, to determine whether variations 

 aoted are local and essentially individual or, rather, are susceptible 

 of correlation with geographic and physiographic factors. 



In this connection the importance of further field work should 

 not be underestimated. With the important exception of Santo 

 Domingo ami certain large area- in Cuba the West [ndies have been 

 fairly well covered within recent year-. There remain on the North 

 American continent Nicaragua, Salvador, Honduras, and the vast 

 humid region of eastern Mexico. To the extreme -<>uth i- Panama. 

 connecting geographically the two continent-, it- flora nearly un- 

 known hut almost certainly containing the strong South American 

 element noted in that of Costa Rica immediately t<> the north. The 

 exploration of eastern Mexico at mid-elevation- toward the low- 

 lands seems especially desirable in order to bring to light many of 

 the species described during the first half of the last century. Ex- 

 ploration of the other regions mentioned, particularly of Panama, is 

 hardly less important, a- certain to afford data bearing upon larger 

 problem-. 



The -writer wishes to extend his thanks to the cm i rat or- of the 

 herbaria mentioned later for courteously placing at hi- disposal for 

 study numerous specimens which have been of material assistance. 



ASPLENIUM SALICIFOLIUM AND CONFUSED SPECIES. 



The Asplenium salicifolium of Linnaeus has been almost uni- 

 versally unidentified. It was founded upon Plunder's plate 60, rep- 

 resenting a plant described by Plunder with the remark that he had 

 found it at "several places in the French islands of America." In 

 identifying the Linnaean species, then, we should expect to associate 

 this name with no very uncommon plant of the West Indie-. To 

 assist US there is a passable figure, somewhat idealized but yet -bow- 

 ing a plant since many times collected and rarely if ever referred t«- 

 under its right name — commonly, rather, a- Asplenium auriculatum 

 Sw.. a name given originally to Brazilian specimens. Ample Brazil- 

 ian material, lacking in American herbaria, might -how the true .1. 

 auriculatum to be a different species from the West Indian specimens 

 passing under that name, though this i- certainly to be doubted; but 

 in any event these West Indian specimens undoubtedly represent the 

 true Asplenium salicifolium of Linnaeus, a- the following note- are 



intended to -how. 



