Entoloma cf. appressum (Largent) Noordel. & Co-David

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 : 233

15. Entoloma cf. appressum (Largent) Noordel. & Co-David (in Co-David et al. 2009: 147–176). FIGURE 15 .

≡ Inocephalus appressus Largent (1994: 400)

Description:— Pileus 18 mm diam., plano-convex, depressed, hygrophanous, translucent-striate at margin up to half the radius when fresh, elsewhere dull, appressed-fibrillose, smooth, dark orange-brown with yellow tinges, paler towards margin. Lamellae emarginate, subdistant, ventricose, pale pinkish brown, edge eroded, concolourous. Stipe 40 × 2 mm, central, cylindrical, equal, glabrous, polished, dark orange-brown, with white tomentum at the base. Context thin, 1 mm broad, pale greyish brown. Odour slightly farinaceous. Taste slightly farinaceous.

Basidiospores (7.2–) 7.6–9.6 × (6.4–) 7.2–7.6 (–8.0) μm, Lm = 8.5, Wm = 7.3, Q = 1.0–1.2, isodiametrical to subisodiametrical, 5–6, rarely 7–angled in side-view, colourless. Basidia 26–37 × 9–15 μm, 2- and 4-spored, clavate, colourless, clamped. Pleurocystidia absent. Cheilocystidia 26–68 (–90) × 6–18 μm, utriform to lageniform with elongated neck, some with subcapitate or rostrate apex, colourless, mixed with basidia. Pileipellis a cutis in transition to a trichoderm, terminal elements 24–80 × 12–26 μm, cylindrical, ellipsoid, some with mucronate apex, with yellowish vacuolar pigment and scarce yellowish encrusted pigment. Caulocystidia absent. Clamp-connections present, but scarce.

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

Material studied:— MEXICO. Jalisco, Municipality of Tequila, volcán de Tequila, km 12 road to microwave transmission tower, 9 September 2012, D. Montañez 198 (IBUG!).

Comments:—Using Largent (1974) this collection could readily be identified as Inocephalus appressus , based on the dark orange-brown basidiome, appressed-fibrillose pileus, the subisodiametrical basidiospores, and the presence and shape of the cheilocystidia. The Mexican collection deviates slightly in having smaller basidiospores. Since this species has only been recorded from the type locality, we do not know much about the variability of this character. Originally, this species was found in a cedar wood in Washington State, USA. Similar species are Entoloma cupressum (Largent) Noordel. & Co-David with a dull pileus, occurring in Cupressus forest, and E. fabaceolum (Largent) Noordel. & Co-David (in Co-David et al. 2009) with a scabrose pileus at the centre and a distinctive fabaceous smell ( Largent 1994).

Figures

FIGURE 15. Entoloma cf. appressum. a. Basidiospores. b. Basidia and basidiole. c. Cheilocystidia. d. Pileipellis. All 1000×, except basidiospores 3000×. Drawings by Diego Montañez and Machiel Noordeloos.