Fink: Problems of North American Lichenology 29 



so much careful microscopic work, but no one can hope to 

 contribute largely to a knowledge of our crustose lichens, which 

 are least known, without being a careful student of his material 

 as well as a collector. 



The thing most needed, however, for the systematist, is a 

 reliable manual of North American lichens and monographs 

 of the genera. The need of a manual is so great, that there 

 would be ample excuse for one who might be inclined to under- 

 take such a work to begin at once ; but, in the present state of 

 North American lichenology, the task could be only very imper- 

 fectly performed at best. There is not a monograph of a single 

 genus of lichens for North America, though some monographs by 

 Europeans treat our species in a very imperfect way. Nor can 

 the monograph of the genus Arthonia by Henry Willeyf be con- 

 sidered as more than a compilation. There is here a rich field 

 for the trained systematist who has access to the centers of 

 botanical activity, large herbaria and libraries. Without these 

 facilities creditable work in systematic lichenology is no longer 

 possible, whatever may be the ability and training of the worker. 



Another matter of prime importance is the accumulation of a 

 knowledge regarding the literature of American lichenology. 

 There should be definite historical statement, a list of all species 

 described as new from our territory, a list of all first mention 

 of species from North America, a bibliography as complete as 

 can be made, and even a compilation of all lists of lichens pub- 

 lished as occurring on American territory. It is known to many 

 workers that the writer has been at work on the bibliography and 

 the listing of new species for several years. However, though the 

 titles now number somewhat less than six hundred, every effort 

 to close the work for publication has resulted in finding it too 

 incomplete for that purpose. The larger and less interesting 

 and useful task of compiling all lists published has not been at- 

 tempted, though the writer is of the opinion that every worker 

 in any field of botanical taxonomy should have such lists at 

 hand, however imperfect the determinations may be upon which 

 the lists rest, and however little confidence may be placed in 



f Willey, Henry. A Synopsis of the Genus Arthonia. i-vi and 1-62. 

 New Bedford, Mass., E. Anthony & Sons. 1890. 



