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Page number:539 
Remarks (internal):Stropharia agaricoides presents a set of features that warrants its distinction from the remaining species of the genus: basidiomes resembling species of Agaricus, reddish pileus, fleshy and grooved annulus, short basidiospores, and especially for the small pyriform, sphaeropedunculate cheilochrysocystidia.
Stropharia variicolor Desjardin & Hemmes recently described from Hawaii is macroscopically similar; however in S. variicolor the pleurochrysocystidia are mucronate and the cheilocystidia are not as chrysocystidia (Desjardin and Hemmes 2001). The habitat differs strongly because this species grows on horticultural debris in tropical zone.
Another species from Araucaria forests, S. acanthocystis Cortez & R.M. Silveira, presents similar basidiospores and pyriform cheilocystidia, but the latter are cheiloleptocystidia and macroscopically they differs on pileus color (yellowish brown in S. acanthocystis) and the annulus (absent in the latter, Cortez and Silveira 2007).
Stropharia agaricoides is superficially similar to young specimens of S. rugosoannulata Farl. in Murrill but differs strongly from mature specimens, which are larger and robust and microscopically form larger basidiospores (10-14 µm long) and fusoid cheilocystidia (Noordeloos 1999, Cortez and Silveira 2008).
Stropharia coronilla (Bull.) Quél. presents a similar stature, basidiospores and pleurocystidia, but the pileus is pale yellow and the cheilocystidia are larger (21-56 µm long), clavate and not of chrysocystidia type (Noordeloos 1999, Cortez and Silveira 2008).
 
Description type:Original description 
Description:Stropharia agaricoides P.S. Silva, Cortez & R.M. Silveira, sp. nov. Figs. 1-7
MycoBank MB 511916
Pileus 60 mm diam, brownish orange (KW 7C8) in the center, becoming reddish orange (KW 7A6) toward the margin, smooth and moist surface, margin entire, crenulate, nonstriate, context white (KW 7A1), fleshy. Lamellae adnexed, brownish gray (KW 7C2) to dull lilac (KW 16C3), close, membranous; margin entire, whitish. Stipe 60 x 10 mm, central, cylindrical, white (KW 7A1) to pinkish white (KW 7A2), surface smooth to scattered fibrillose, fibrous consistency, white rhizomorphs abundant at the stipe base. Veil present as pinkish white (KW 7A2) velar remnants appendiculate on pileus margin, and also forming a fleshy annulus, white (KW 7A1) to pinkish white (KW 7A2), grooved above. Spore print grayish violet (KW 17E5). Basidiospores 7-8.5(-9) x 4-6 µm (Q = 1.40-1.88, Qm = 1.68, n = 25), ellipsoid to ovoid in both frontal and side view, yellowish brown under KOH preparations, walls thickened and with a reduced apical germ pore. Basidia 18-29 x 5-8 µm, cylindrical to clavate, hyaline, tetrasporic. Pleurochrysocystidia 25-35(-48) x 8-13 µm, clavate to fusoid, with conspicuous yellowish content. Cheiloleptocystidia 13-19 x 6-12 µm, globose to pyriform, sphaeropedunculate, hyaline, scattered among the cheilochrysocystidia. Cheilochrysocystidia 17-25(-27) x 10-15 µm, globose to pyriform, similar to the leptocystidia in shape, but with amorphous yellowish content. Pileipellis formed by prostrate, hyaline, thin-walled hyphae, 6-12 µm diam. Context composed of interwoven, hyaline, filamentous, 9-19 µm diam hyphae. Hymenophoral trama regular to subregular, formed of filamentous to inflated, hyaline, 8-14(-16) µm diam hyphae. Stipitepellis composed of parallel, hyaline, thin-walled hyphae, 5-10(-14) µm diam. Caulocystidia not found. Acanthocytes present on rhizomorphs.
Habitat. - Solitary on the litter and soil in subtropical native forests with Araucaria.
Distribution. - Known only from the type locality (FLONA-SFP).
Specimen examined: Brazil. Rio Grande do Sul State: SÀ£o Francisco de Paula, FLONA-SFP, 30 Jun 2007, P.S. Silva 191/07 (ICN 139.385 - Holotype here designated).
Etymology. - Resembling a species of genus Agaricus Fr.

 
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