Entoloma sericeum Quélet (1872: 119)

Montañez, Diego, Noordeloos, Machiel E., Rodríguez, Olivia, Vargas, Ofelia & Guzmán-Dávalos, Laura, 2016, Notes on the genus Entoloma (Basidiomycota, Agaricales) in two volcanic areas of Jalisco, Mexico, Phytotaxa 277 (3), pp. 211-236 : 221-222

7. Entoloma sericeum Quélet (1872: 119) , FIGURE 7 .

≡ Agaricus sericeus Bulliard (1789 : tab. 413)

≡ Rhodophyllus sericeus (Quél.) Quélet (1886: 59)

≡ Nolanea sericea (Quél.) P.D. Orton (1960: 179)

Description:— Pileus 13–30 mm broad, convex, plano-convex to plane, some with small papilla, hygrophanous, dull or translucent-striate just at the margin, glabrous to slightly fibrillose, smooth, chocolate brown or dark greyish brown, paler at the margin. Lamella e adnate to emarginate, subdistant, ventricose, pinkish brown then pink, edge entire or eroded, concolourous. Stipe 28–40 × 2–4 mm, central, cylindrical, equal, slightly fibrillose, with pruinose apex, smooth or finely longitudinally striate, concolourous with the pileus, paler at the apex. Context thin, pale to dark greyish brown. Odour none to farinaceous. Taste none to farinaceous.

Basidiospores (6.4–) 7.2–8.8 (–9.2) × 6.4–8.0 μm, Lm = 7.9, Wm = 7.2, Q = 1.0–1.2, isodiametrical, some subisodiametrical, 5–7 angled in side-view, colourless. Basidia 22–47 × 8–12 μm, 4-spored, clavate or cylindro-clavate, colourless or yellowish, clamped. Pleurocystidia absent. Cheilocystidia absent. Pileipellis a cutis to ixocutis, hyphae 2–9 μm wide, with abundant yellowish encrusted pigment. Caulocystidia absent or like undifferentiated terminal elements 28–53 × 8–12 μm, cylindrical to cylindro-clavate, colourless, scattered at the stipe apex. Clamp-connections present in hymenophoral trama, absent elsewhere.

Habit and habitat:—Gregarious, on soil, in Pinus - Quercus forest with cloud forest influence.

Material studied:— MEXICO. Jalisco, Municipality of Zapotlán el Grande, cañón El Floripondio, slopes of Nevado de Colima, 11 September 2012, D. Montañez 214 (IBUG!).

Comments:— Entoloma sericeum is a very variable species, mainly characterized by the dark brown pileus and stipe, isodiametrical basidiospores (7.0–10.5 × 6.5–9.5 μm), and pileipellis hyphae with encrusted pigment ( Noordeloos 1992). It has a wide distribution and has been recorded from Europe, North America, and Australia in a wide range of habitats and climate zones ( Noordeloos 1992, Largent 1994, Noordeloos & Gates 2012). Vila et al. (2013), in a preliminary attempt to disentangle the taxa in the sericeum complex, described and mentioned a number of similar species, such as E. llimonae Vila, F. Caball., Català & J. Carbó with larger basidiospores, E. minutisporum (Vila & Llimona) Carbó, Vila, Català & F. Caball. with smaller basidiospores, E. ortonii Arnolds & Noordeloos (1979) with a pale brown stipe and pileipellis hyphae with plasmatic and encrusted pigment, and E. subsericeoides (Largent) Noordel. & Co-David in Co-David et al. (2009) with heterodiametrical basidiospores, pileipellis hyphae with both types of pigment, and absence of clamp-connections. Continued research will probably reveal interesting taxonomic and biogeographical patterns in this particular group of species. Entoloma sericeum was previously cited for Mexico by Pérez-Silva et al. (2011) in Estado de México.

Figures

FIGURE 7. Entoloma sericeum. a. Basidiospores. b. Basidia. c. Cheilocystidia. d. Caulocystidia.All 1000×, except basidiospores 3000×. Drawings by Diego Montañez and Machiel Noordeloos.