STUDIES OF TROPICAL AMERICAN FERNS-NO. I. 



P»v William R. Maxon, 



INTRODUCTION. 



In this and following papers it is the purpose of the writer to pre- 

 sent under a collective title some results of studies of tropical Amer- 

 ican fern-, especially those of the West Indie-. Mexico, and Central 

 America. The matter is designed to include notes on some of tie- 

 earlier species, corrections in nomenclature, descriptions of new 

 species and. when material warrants, revisions of certain genera and 

 smaller groups of species. 



A considerable number of the early species, of those even which 

 have figured longest in literature, are -till imperfectly understood 

 and not infrequently appear under wrong names. To determine with 

 exactness these historic species is of much taxonomic importance. 

 The accomplishment of this, often a matter of extensive detail, is 

 made vastly easier than formerly to American students by the large 

 series of specimens gathered in recent year- by American collector-: 

 but even with these at hand there remain other consideration- which 

 render the serious study of so variable a group more than ordinarily 

 difficult. As chief of these — aside from the usual insufficiency of the 

 diagnoses and the location of the historic early collection-, with their 

 numerous type- and frequently cited number-, in European her- 

 baria — may be mentioned the lack of attention given in the past to 

 the matter of type localities and the failure to appreciate the fact oi 

 the more or less definite geographical distribution of species. From 

 this there ha- resulted the greatest confusion. 



To illustrate: The extent of variation even in a suite of specimens 

 from a -ingle locality in tropical America, these known absolutely 

 to constitute but a single variable though definitely restricted species, 

 is sometime — -and this in no one genus and no one tribe little short 

 of astounding. To such a series known under one name may have 

 been joined a closely allied group from some other and perhaps dis- 



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