The veiled species of Hebeloma in the western United States / Alexander H. Smith, Vera Stucky Evenson, and Duane H. Mitchel.

The Subgenus
HEBELOMA
The features of this taxon are the presence of a fibrillose veil,
often scanty, that when broken usually leaves remnants on the margin
of the pileus and/or on the stipe. A second character is the presence of
typically fusoid-ventricose, often narrow and greatly elongated cells
among those along the edges of the gills (the cheilocystidia). The fusoid-ventricose cystidia are abundant to rare depending on the species
being examined.
The type species of the genus is Hebeloma fastibile (Pers.: Fr.)
Kummer. The subgenus containing the type species of the genus automatically bears the name of the genus.
Key to Major Infrageneric Taxa of HEBELOMA
1. Veil present, usually fibrillose to cortinate................. Subgenus Hebeloma
1. Veil absent (but see H. insigne which has a "false" veil)............................ Subgenus Denudata (not discussed in this volume)
Key to Sections of Subgenus HEBELOMA
1. Spores in profile view bean-shaped to elliptic or ovate, the apex
+ rounded (see text figs. Al-10).................. Section Mesophaea (p. 26)
1. Spores + inequilateral in profile and narrowed to a blunt apex or
apex + snoutlike.................................. Section Hebeloma (p. 84)
Key to Subsections of Section MESOPHAEA
1. Spores 10-15 tpm long or longer................ Subsection Subviscidae (p. 26)
1. Spores 7-10 (11) pxm long.....................Subsection Mesophaeae (p. 35)
Key to Subsections of Section HEBELOMA
1. Pileus white to pallid or cream color................ Subsection Pallidae (p. 84)
1. Pileus more highly colored when young than in above choice................. 2
2. When fresh the odor fragrant to pungent-aromatic........................................... Subsection Praeolidae (p. 88)
2. Not as above (the odor if present ~ pungent to radishlike)............... 3
3. Spores 7-10 (11) pxm long...................... Subsection Mesosporae (p. 96)
3. Spores (9) 10-15 lxm or longer............... Subsection Magnisporae (p. 108)

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