Entoloma chalybeum (Pers.) Noordeloos (1982a: 162)

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 : 227-228

11. Entoloma chalybeum (Pers.) Noordeloos (1982a: 162) , FIGURE 11 .

≡ Agaricus chalybeus Persoon (1801: 343)

≡ Leptonia chalybea (Pers.) P. Kummer (1871: 96)

Description:— Pileus 11–35 mm broad, conic, convex to convex-campanulate, some truncate, dry, non translucent-striate, centre velutinous, elsewhere fibrillose-squamulose to fibrillose, striate, blackish blue, violet black, or black. Lamellae emarginate, subdistant, ventricose, blue then pink, sometimes with bluish tinges when mature, edge entire to slightly eroded, concolourous or blackish blue in some sections. Stipe 20–40 × 2–5 mm, central, cylindrical, slightly broadening at the base, polished, glabrous, with pruinose apex, smooth, concolourous with pileus, some whitish at the base. Context very thin, 1 mm broad, whitish with blue tinges. Odour none or slightly farinaceous. Taste none or slightly farinaceous.

Basidiospores 8.8–12.8 × 6.4–9.6 μm, Lm = 10.8, Wm = 8, Q = 1.2–1.8, heterodiametrical, some subisodiametrical, 5–7 angled in side-view, colourless. Basidia 23–43 × 8–14 μm, 2- and 4-spored, clavate to ellipsoid, colourless or with yellowish vacuolar pigment, clampless. Pleurocystidia absent. Cheilocystidia 13–84 × 5–13 μm, clavate to cylindro-clavate, some septate, colourless or with greyish brown plasmatic pigment, forming a sterile layer. Pileipellis a trichoderm at centre, terminal elements 19–80 × 8–31 μm, cylindro-clavate, clavate, or ellipsoid, some in chains made up of short and inflated elements, a cutis at margin; with blue plasmatic pigment. Caulocystidia 16–52 × 5–13 μm, clavate to cylindro-clavate, colourless or blue, in dense groups or a palisade at the stipe apex. Clamp-connections absent.

Habit and habitat:—Gregarious, on soil, in Quercus and Pinus forest.

Material studied:— MEXICO. Jalisco, Municipality of Tequila, volcán de Tequila, km 11 road to microwave transmission tower, 9 September 2012, D. Montañez 197 (IBUG!).

Comments:—Collections with the above combination of blue basidiomata, including the gills, which are lined with dark pigmented cheilocystidia invariably key out as the morphospecies Entoloma chalybeum , a common species in Europe and North America ( Largent 1974, Noordeloos 1992). Similar species occur in Australia ( Noordeloos & Gates 2012). Unpublished molecular studies, however, show that there is considerable genetic variation in this morphospecies. Unfortunately, at present it is too early to use this information to identify the Mexican material, which therefore is provided with the name E. chalybeum . Similar species also recorded from Mexico are E. serrulatum (Fr.) Hesler (1967) with a blackish blue, serrulate lamellae edge; E. subcaeruleum Hesler (1967) with a pale blue with olive green tinges pileus and decurrent lamellae, lignicolous, and occurring in tropical places ( Murrill 1917, Hesler 1967, Largent 1977); and E. howellii (Peck) Dennis (1953) from tropical places and without cheilocystidia ( Cifuentes & Guzmán 1981).

Figures

FIGURE 11. Entoloma chalybeum. a. Basidiospores. b. Basidia. c. Cheilocystidia. d. Pileipellis. e. Caulocystidia. All 1000×, except basidiospores 3000×. Drawings by Diego Montañez and Machiel Noordeloos.