14 GENERAL CONSIDERATIONS 



stipe. The European H. ligatus apparently has a fibrillose but not a 

 gelatinous veil, as does our own H. subalpinus. H. hypothejus and H. 

 olivaceoalbus have both types, and H. fuligineus has only the gelati- 

 nous veil. H. speciosus and its variants seem to be intermediate in that 

 an inner veil is present in one variant along with the gelatinous veil. 

 H. laurae, H. variicolor, and H. subsalmonius have the remains of the 

 gelatinous veil only over the lower part or base of the stipe. In sub- 

 section Camarophyllus, by definition, the gelatinous outer veil is ab- 

 sent, though a fibrillose "dry" veil may be present. 



In section Camarophyllopsis the stipe is typically dry and veils are 

 lacking, but in section Hygrocybe the stipe may be very slimy to 

 merely viscid from an outer gelatinous cortex of appressed hyphae or a 

 structure termed an ixotrichodermium which is discussed in detail un- 

 der microscopic characters. We have no data as to how this type of sur- 

 face evolved, but it seems unlikely that this type of layer is derived 

 from a veil. 



The shape of the stipe and its diameter have taxonomic value 

 within broad limits. The diameter, as given in our description, is taken 

 near the apex, and shape is indicated from this point down, i.e., nar- 

 rowed to a pointed base, clavate (means enlarged below) or fusiform, 

 meaning enlarged in the middle and tapered both ways. 



MICROSCOPIC CHARACTERS 

 Spores 



Spore characters are now considered among the most fundamental 

 of all those characters used in the classification of the Basidiomycetes; 

 but because of remarkable homogeneity in Hygrophorus, they are not 

 as important to the classification of its species, let us say, as the spores 

 of Inocybe are to the arrangement of species in that genus. 



Historically, spore size and shape, after the color of the spore de- 

 posit (which is typically white), were among the first features of the 

 spores to be widely used and are still important in Hygrophorus at the 

 species level. Spore size and shape should be determined from spores 

 from a deposit since by definition these are mature. In practice, how- 

 ever, one frequently crushes a small piece of gill tissue from a mature 

 cap. A deposit of spores from a pileus with 4-spored basidia, when the 

 spores are measured, will give a simple, unimodal curve. In spores 

 between 6 and 14 /x long the expected variation is a micron or two on 

 either side of the peak, the variation being greater for the larger 

 spores. Corner (1936), and later Dennis (1953), described an unusual 

 situation in H. firmus and its variants, in which two sizes of basidia oc- 



