Summary:
Sphagnurus paluster is characterized by parasitism on Sphagnum. (According to Smith(15) it kills Sphagnum in distinct areas around it where moss becomes gray; fruiting bodies often occur close to the living moss.) Other features include a hygrophanous, grooved cap that is gray to dark umber brown, at first with a whitish bloom, unchanging flesh, whitish to grayish gills, a fragile stem paler than the cap and pruinose when young, a rancid-farinaceous odor, and elongate elliptic, smooth, inamyloid spores. The online Species Fungorum, accessed February 9, 2016, gave the current name as Sphagnurus paluster (Peck) Redhead & V. Hofst. but MycoBank gave Lyophyllum palustre (Peck) Singer as the current name on the same date.

Gills:
adnate or with a slight tooth, close to subdistant, narrow to broad, rather thick at times and interveined; "pale smoke gray" becoming watery gray, (Smith), deeply emarginate-adnate, whitish to grayish, (Moser), slightly notched to finely adnexed, 20-25 reaching stem, broad, often forked, 1-7 subgills between neighboring gills; whitish; edges smooth, (Breitenbach)

Stem:
4-10cm x 0.2-0.5(0.7)cm, fragile, hollow; gray, paler than cap; white-pruinose when young becoming bald and watery; "base usually coated with white mycelium", (Smith), 5-10cm x 0.1-0.3cm, fragile; gray, gray-brown; pruinose when young, (Moser), 3-7cm x 0.2-0.4cm, cylindric, base sometimes slightly widened, stem fragile, hollow; "brownish, gray-whitish fibrillose", (Breitenbach)

Odor:
farinaceous (Smith), floury-rancid (Moser), farinaceous (Breitenbach)

Taste:
farinaceous (Smith), "mild, farinaceous-rancid", (Breitenbach)

Microscopic spores:
spores 6-8 x 4-4.5 microns, elliptic, smooth, inamyloid; basidia 4-spored, 18-22 x 6.5-8 microns, pleurocystidia none, cheilocystidia basidia-like, (Smith), spores 5.5-8.5 x 3-5 microns (Moser), spores 6.1-8.5 x 3.1-5.0 microns, elliptic, smooth, iodine negative, some with droplets; basidia 4-spored, 28-35 x 5.5-8 microns, narrowly clavate, with siderophilic granules, with basal clamp connection; pleurocystidia and cheilocystidia not seen; cap cuticle of parallel [horizontal] hyphae 3-11 microns wide, occasional hyphal ends exserted and clavate; clamp connections mentioned for cap cuticle and basidia (Breitenbach)

Spore deposit:
white (Breitenbach)

Notes:
Smith says it is "to be expected wherever sphagnum bogs are found in our northern temperate regions". Breitenbach (3) give the distribution as North America, Europe, and Asia. A collection by Paul Kroeger from BC is at the University of British Columbia.

EDIBILITY

Synonyms and Alternate Names:
Tephrocybe palustris (Peck) Donk