MYCOLOGIA 



Vol, XIII JULY-SEPTEMBER, 1921 Nos 4-5 



MASSACHUSETTS SPECIES OF H 



P. J. Anderson and Marguerite G. Ic: 



(With Plates ii and 12) 



INTRODUCTION 



Helvetia is a small genus containing less than fifty species, 

 only a small part of which occur in any one locality. They are 

 not so common in New England but that the fungus hunter ex- 

 periences a thrill of pleasure on finding one and the day is con- 

 sidered eminently successful if he has picked up more than two 

 or three species. In view of the small number of known species 

 he anticipates no great difficulty or labor in identifying his col- 

 lections, but soon finds himself confronted with these discourag- 

 ing conditions : ( I ) there is no one place where the descriptions 

 of the known American species are brought together, (2) there 

 is not even a list of the species which occur in America later than 

 that of Underwood (1896) and he gives no keys, descriptions, 

 or figures, (3) the heterogeneous lists scattered through Sac- 

 cardo's Sylloge Fungorum include many species which have been 

 removed from the genus, many others known to be synonyms ; 

 the descriptions are very brief and many of them unsatisfactory 

 even to one quite familiar with the Latin tongue, (4) there is 

 marked confusion in regard both to the delimitation of the genus 

 and more especially of the species, (5) the literature is scattered, 

 contradictory, and much of it not readily accessible, (6) lists 

 other than those of Saccardo are only local, (7) exsiccati speci- 



[Mycologia for May (13: 129-199) was issued June 25, 1921] 



201 



