Agaricus placomyces Peck, Ann. Rep. N.Y. St. Mus. nat. Hist. 29: 40 (1878)  Index Fungorum number: IF 250161
Synonymy: Agaricus placomyces var. microsporus A.H. Sm., Pap. Mich. Acad. Sci. 25: 125 (1940)
:Agaricus placomyces var. flavescens Thiers, Mycologia 51(4): 538 (1960)
Pileus 5.0 cm wide, expanded convex with a low broad umbo, white, flesh having greyish brown scales all over the surface, cap yellow with KOH, radially splitting on maturity. Gills pinkish to light brownish, unequal, free, crowded. Stipe 5.2 cm long and 0.5 cm wide, white, nearly equal ending with a slight bulbous base. Annulus present, white membranous band like with cottony patches. Edibility unknown.
Basidia 17.6–27.2 × 6.4–8.0 μm, clavate, thin walled, hyaline. Sterigmata 1.6 to 2.4 μm long. Basidiospores 4.0–5.6 × 2.4–3.2 μm, avL=4.8, avW=2.8, Q=1.66–1.75, elliptic, apiculate, monoguttulated. Spore print brown. Pileus and stipe context hyphae 6.0 to 8.0 and 4.0 to 24.0 μm respectively, hyaline, septate. Annulus hyphae 4.0 to 14.0 μm, hyaline, branched, septate.
Material Examined : India, Jammu & Kashmir, Jammu, R.S. Pura, coprophilous, single, 6 Jul 2015, Roshi Sharma & Y.P. Sharma, HBJU 406.
Distribution: This species has been earlier reported from Central India, Maharashtra.
Notes: This species have been reported from Central India by Karwa & Rai 2010. The present collection is found to be a new record for Jammu & Kashmir. The species closely resembles with the description given by Bessette et al. (1997) except for habitat difference as the current specimen was found to be coprophilous whereas Bessette et al. (1997) reported it to be lignicolous.
FIGURE. c Basidiocarps of Agaricus placomyces in natural habitat. d Undersurface view of A. placomyces showing gills.
FIGURE. Agaricus placomyces a) basidia b) basidiospores c) pileus context hyphae d) stipe context hyphae e) annulus hyphae. Scale bars: a–e = 10 μm.