42 GENERAL CONSIDERATIONS 



this family" (p. 142). His discussion is concerned more with separat- 

 ing the family from the Tricholomataceae. 



As for phvlogenetic relationships of the Hijgrophoraceae to the 

 Tricholomataceae, the section Hygrocybe seems to us to hold the best 

 possibilities, especially through the section Adonidae of Mycena. In 

 Mycena it is important to measure basidia for a length-to-width ratio, 

 and compare this with the same ratio for basidia of the smaller species 

 of section Hygrocybe. In Mycena amabilissima the hymenophore is 

 waxy — a fact which indicates a breakdown of this character in the 

 genus Hygrophorus. However, we do not find a similar relationship to 

 Laccaria, or to Clitocybe or Tricholoma, and we concur with Singer 

 (1951, p. 142) that such relationships are improbable. Nevertheless, as 

 further studies of the Tricholomataceae are made, the possibility of 

 such relationships should be kept in mind, for at this time it is unreal- 

 istic to believe that an inventory of the North American representa- 

 tives of this family is near completion or that all known species have 

 been studied carefully enough in this respect. We do not regard the 

 peculiar Clitocybe gomphidioides as an established relationship of 

 Clitocybe to species of section Hygrophorus, but rather as a singular 

 species of uncertain relationship. Although the hymenophore is some- 

 what waxy in Gomphidius, its dark-colored spores and peculiar cystidia 

 indicate that it is not related to the Hijgrophoraceae, as Singer ( 1951 ) 

 has pointed out. 



In summary, we place Hygrophorus in a position intermediate be- 

 tween Cantharellus on the one hand and the Tricholomataceae, as de- 

 fined by Singer, on the other. We recognize a number of lines of evolu- 

 tion in the genus leading to the highly specialized species and with 

 one real possibility of a true connection to the Tricholomataceae 

 through the genus Mycena. 



MATERIALS STUDIED 



It is impossible to state precisely the numbers of Hygrophorus col- 

 lections we have studied in the course of our investigations on this 

 genus, but the numbers of collections cited is approximately thirty-two 

 hundred. As in any investigation of this sort, much more material is 

 handled in the fresh condition than is finally filed in the herbarium. 

 More important than the total number of collections cited is the num- 

 ber of plant associations from which the collections have been made. 

 Since Hygrophori are primarily forest fungi, forest associations and 

 si mil) associations are most important. These are discussed under eco- 

 logical considerations. 



