SUBSECTION IIYGROPIIORUS 283 



Spores 8-10(11) X 4.5-6 /x, ellipsoid, smooth, pale yellowish in 

 Melzer's reagent. Basidia 46-57 X 6-8 fx, 2- and 4-spored. Pleuroevstidia 

 and cheilocystidia none. Gill trama divergent, hyphae 3-7 /x broad. Cu- 

 ticle a gelatinous zone 200-900 /x thick, hyphae repent on the surface 

 but more or less erect below but not a palisade, narrow (3-5 /x). No 

 hypodermium evident. Pileus trama of hyphae which are radial and 

 parallel to only slightly interwoven. Clamp connections present in the 

 cuticular hyphae. 



Habit, Habitat, and Distbibution — Gregarious or subcaespitose 

 under spruce and pine, Tennessee, Georgia, Idaho, Wyoming, Oregon, 

 and California; also Europe, September-January. 



Matebial Studied — caitfobnia: Pusateri, Sequoia National Park, 

 Fall 1941. geobgia: Hesler 22234. idaho: Smith 46284, 46467, 59707. 

 obegon: Gruber, Takilma, Nov. 28, 1942; Smith 24956, 24999, 27960, 

 28136. Tennessee: Hesler 17252, 17270, 19560, 20241, 20774, 22224, 

 22234, 22564. Wyoming: Kanouse, Medicine Bow Mts., Sept. 7, 1923; 

 Kauffman, same. Belgium: Heinemann 1520. 



Obsebvations — Hygrophorus gliocyclus is distinguished from its 

 close relative H. flavodiscus on the character of the lamellae and 

 spores. The lamellae of H. flavodiscus are at first pinkish, then fading 

 to whitish, and its spores are 6-8 X 3.5-5 /x. Moreover, in H. flavodiscus, 

 when fresh, the pileus is white with a pale-yellow or reddish-yellow 

 disc. In general, the stipe of H. flavodiscus is more slender than in H. 

 gliocyclus. 



As we interpret this species, following American usage of the name, 

 it is a robust Hygrophorus very readily attacked by insect larvae and 

 occurring principally with pine. This we realize is not entirely consist- 

 ent with treatments by European authors. The problem needs further 

 study. 



SERIES OLIVACEOUMBRINI (Fr.) stat. nov. 



Subsection Olivaceoumbrini Fries, Hymen. Eur., p. 409. 1879. 

 Characters as given in key to series, page 249. 

 Type species: H. olivaceoalbus Fr. 



Key to Species 



1. Lamellae crowded and sinuate; spores 4-5 X 3.5-5 /x 



170. H. subpratensis 



1. Lamellae and spores not as above 2 



2. Odor amygdaline; pleuroevstidia and cheilocvstidia 46-60 X 4-6 jx 



171. H. amygdalinus 



2. Not as above 3 



