E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Features include 1) small size, 2) a hygrophanous, reddish brown, subviscid to lubricous cap, 3) adnate, often mottled gills that are fuscous gray to dull buff or dark violaceous brown, with white edges, 4) a whitish or almost cap-colored stem, 5) growth on dung, in grassland, 6) a dark purple brown spore deposit, and 7) microscopic characters including angular spores. Deconica argentina is rare in the Pacific Northwest.

Deconica argentina has been found in WA, CA, MI, Mexico, Argentina, Brazil, Colombia, Venezuela, and Switzerland, (Guzman(1)). A Paul Kroeger collection from BC is deposited at the University of British Columbia (as Psilocybe).

Gills:
broadly adnate; "fuscous gray to dull buff or dark violaceous brown, with white edges", frequently mottled

Stem:
(1.5)2-4.5(5)cm x (0.13)0.2-0.3cm, equal or eventually somewhat widened at top, hollow; whitish or almost cap-colored or more reddish brown; smooth or slightly fibrillose

Veil:
arachnoid [cobwebby] white mass when young, but stem without remains when mature

Odor:
slightly fungoid

Taste:
slightly fungoid

Microscopic spores:
spores (11)12-15(18.6) x (9)9.6-10.2(12) x 7-8.5 microns, "strongly subhexagonal or subrhomboid in face view", subelliptic in side view, light to dark yellowish brown, thick-walled, with broad truncate germ pore; basidia 4-spored, 24-32 x 10-13 microns, colorless, ventricose subpyriform, [somewhat pear-shaped and wider in middle], sometimes with a slight medial constriction; pleurocystidia absent, cheilocystidia abundant, 22-45 x 4.5-10 microns, colorless, thin-walled, "fusoid-ventricose or sublageniform to lageniform", with long neck 3-8 microns broad "and with obtuse, subglobose to globose apex"

Spore deposit:
dark violaceous brown or dark purple brown