Entoloma griseofibrillosus A. Izhar, T. Qasim, M. Asif, Niazi & Khalid 2023, sp. nov.

Entoloma griseofibrillosus A. Izhar, T. Qasim, M. Asif, Niazi & Khalid sp. nov.

(Figs. 3 & 4) MycoBank no:—MB831141

Diagnosis:— Pileus convex, centrally depressed with greyish brown radiating fibrils; adnate lamellae; stipe cylindrical; basidiospores sub-isodiametric with 6–8 round angles, large (6.8–8.9 × 6.1–8 μm), hyaline, thick-walled; basidia and crassobasidia of almost similar size; cheilocystidia cylindrical, sinuose, few sublageniform, pileipellis a cutis made up of irregular hyphae.

Holotype:— PAKISTAN. Punjab, Hiran Minar, Sheikhupura, at 236m a.s.l. (above sea level), 2 nd August 2017, Aiman Izhar, SKP 122, (LAH35884). GenBank MN 240807 (nrITS), MN240834 (nrLSU).

Etymology:— “ griseofibrillosus ” in Latin, refers to the greyish fibrils on the pileus surface.

Description:— Basidiomata small, omphaloid. Pileus 10–30 mm diam; opaque, hemispherical when young becoming broadly convex, flat and centrally depressed at maturity, hygrophanous, non-translucent, non-striate margins, upon maturity becoming upturned and undulating, surface dry, fibrillose, dark brown (5YR 3/1) at centre of pileus becoming appressed brown or greyish brown (5YR 4/1), covered with shiny fibrils with a white pruina, cracked at maturity, context whitish and thin, margins entire to wavy, incurved initially but later becoming upturned. Lamellae adnate, ventricose, distant, light greyish white (7.5YR 7/1) with whitish appearance, moderately thick, margins entire or eroded, lamellulae in 1–3 tiers. Stipe 4–6 cm in length × 0.3–0.5 cm, sub-cylindrical, hollow, context thin, dry, surface greyish brown (7.5YR 6/1) covered with a greyish-white pruina, with greyish brown fibrils beneath, base slightly equal to slightly broad.

Basidiospores (6.8–) 7.4–7.9 (8.9) × (6.1) 7–7.4 (8) μm, avl × avw = 7.6 × 7.2 μm; Q= 0.92–1.19; Qav= 1.06 + 0.07, isodiametric to sub-isodiametric, angular with 6–8 rounded angles, but angles not very prominent, thick-walled, hyaline in 3% KOH, no reaction in Melzer’s reagent, apiculate, smooth, monoguttulate. Basidia (31) 33–35 (–37) × (9) 10.2–10.9 (12) μm, avl × avw = 34 × 10.5 μm, clavate to sub-clavate or sub-cylindrical, moderately thick-walled, 2–4- spored, smooth, dense oil contents present, with no clamp connections at the base. Crassobasidia (26.6–) 29.7–33.7 (37) × (7.3–) 8.9–10.1 (–10.6) μm, avl × avw= 31.7 × 9.5 μm, sub-clavate to cylindrical, smooth, thick-walled, no oil contents present, base clampless. Cheilocystidia rare, 31– 49.5 × 7.5–10.6 μm, avl × avw = 40.5–9 μm, hyaline in 3% KOH, cylindrical, sinuose, few sublageniform, thin-walled, base clampless. Pleurocystidia absent. Pileipellis 7.7–13.7 μm, avw= 9.8 μm, a cutis of cylindrical hyphae; hyaline in 3% KOH, irregular and overlapping in arrangement, clamp connections not observed, septate, smooth, occasionally brownish encrusted, terminal cells cylindrical or sub-clavate, 38–90 × 8.7–12 μm. Stipitipellis 42.7–90 × 9.4–10.8 μm, parallel, smooth, branched, thin-walled, hyaline in 3% KOH; septate, clamp connections absent.

Habit and habitat:—Saprotrophic, omphalioid, gregarious on moist, loamy soil enriched with nutrients, mostly among the grass.

Additional material examined:— PAKISTAN. Punjab, Hiran Minar, Sheikhupura, at 236m a.s.l., 14 August 2017, Aiman Izhar, SKP-1044, (LAH37159). GenBank ON 573298 (nrITS), ON573336 (nrLSU); ibid. 06 September 2019, SKP-1177, (LAH37158), GenBank ON 573297 (nrITS), ON573335 (nrLSU); Punjab, Lahore, Jallo Park, 217 m a.s.l, 18 th July 2016, Tayyaba Qasim & Abdul Nasir Khalid, JPL4, (LAH10512016), GenBank MN 241256 (nrITS); University of the Punjab, 217 m a.s.l., scattered or in a group in grassy lawns on rich loamy soil, 13 September 2014, Tayyaba Qasim & Abdul Nasir Khalid, PU 14R, (LAH10562014), GenBank MN 241253 (nrITS).

A key to Entoloma species in Entoloma rusticoides-group

1a. Clamp connections present................................................................................................................................................................2.

1b. Clamp connections absent .................................................................................................................................................................3.

2. Pileus campanulate to infundibuliform, 160 mm diameter, gray to bronze brown, hygrophanous; basidiospores 6–9 × 5–8 µm; pileipellis brown pigmented; clamp connections at the base of basidia and stipe tissues................................... E. infundibuliforme

3a. Pileus weakly/non-hygrophanou .......................................................................................................................................................4.

3b. Pileus strongly hygrophanous............................................................................................................................................................5.

4a. Pileus convex, up to 17 mm diameter, greyish brown, without reddish brown tinges; basidiospores 8–11.5 × 7–11 µm; pileipellis light brownish pigmented .............................................................................................................................................. E. almeriense

4b. Pileus convex to flat, 10 mm, brownish, tinges absent; basidiospores 8.3–10 × 7.5–9.1 µm; pileipellis incrusted brownish ............ ................................................................................................................................................................................... E. flossculosum

5a. Cheilocystidia absent.........................................................................................................................................................................7.

5b. Cheilocystidia present .....................................................................................................................................................................16.

7a. Basidiospores subisodiamterical or Heterodiamterical ......................................................................................................................8

7b. Basidiospores isodiamterical ..............................................................................................................................................................9

8a. Pileus convex to plane, 20–55 mm, black brown to greyish brown with brownish tinges; basidiospores 7.5 – 8.5 × 5.7–7.5 µm, pileipellis brown incrusted ............................................................................................................................................... E. costatum

8b. Pileus campanulate to convex, 25 mm, pinkish brown; weakly hygrophanous; basidiospores iso- to heterodiametrical 7.5–11 × 6–8.5 µm; pileipellis pigmented .................................................................................................................... E. incarnatofuscescens

9a. Pileus convex to flat, weakly/non-hygrophanous.............................................................................................................................10

9b. Pileus Conex to umbilicate, strongly hygrophanous ........................................................................................................................13

10a. Stipe filiform, up to 1 mm in diameter ............................................................................................................................................11.

10b. Stipe broader, upto 3 mm in diameter .............................................................................................................................................12.

11. Pileus 10 mm, grayish brown with brownish tinges; basidiospores 8.3–9.3 × 7.2–8.3 µm, Xm= 8.8 × 7.7 µm; pileipellis pigmented brown ............................................................................................................................................................................. E. graphitipes

12a. Pileus 15 mm, dark brownish with reddish tinges; stipe central to eccentric; basidiospores 8.6–10.2 × 7.8–9.8 µm, Xm= 9.6 × 9.1 µm, pileipellis pigmented ......................................................................................................................................... E. phaeocarpum

12b. Pileus 20 mm, brownish grey to black with brown tinges; stipe central; basidiospores 8–10.7 × 6.9–10.4 µm, Xm= 9.3 × 8.7 µm; pileipellis brown encrusted ............................................................................................................................................ E. rusticoides

13a. Stipe 1–2 mm in diameter; habitat on nutrient poor soils or sand...................................................................................................14.

13b. Stipe up to 5 mm wide, habitat on nutrient rich grazed garsslands.................................................................................................15.

14a. Pileus 20 mm wide, dark grey brown with brown tinges, basidiospores 6.5–8.1 × 5.3–7 µm; pileipellis pigmentation of two kinds, membranal pigments coarsely to finely encrusting intracellular pigments as large clots ........................................... E. defibulatum

14b. Pileus 8–13 mm in diameter, light brown to grayish brown, basidiospores 8–9.5 x 6.5–8 µm; pileipellis encrusted ..... E. iodiolens

15. Pileus 15–30 mm in diameter, brown to dark brown without red/brown tinges; basidiospores 7.3–9.3 x 6.4–8; pileipellis encrusted with brown pigments ..................................................................................................................................................... E. sericeoides

16a. Crassobasidia present, basidiospores smaller..................................................................................................................................17.

16b. Crassobasidia absent, basidiospores bigger.....................................................................................................................................18.

17. Pileus hemispherical to broadly convex, 20 mm, dark brown to greyish brown; basidiospores 6.8–8.9 × 6.1–8 µm; pilleipellis occasionally brown incrusted ............................................................................................................................... E. griseofibrillosus

18a. Pileus with red/brown tinges; basidia tetrasporic, rarely bisporic...................................................................................................19.

18b. Pileus lacking red/brown tinges; basidia mono-, bi- or tetrasporic .................................................................................................20.

19. Pileus convex to flat, 20 mm, dark grayish brown; basidiospores 8.5–12.5 × 8–12 µm; pileipellis incrusted with brown pigments; habitat on sandy soils.................................................................................................................................................... E. halophilum

20. Pileus convex, hemispherical to flat, infundibuliform, 15 mm, brownish gray to blackish-grey; basidiospores 9.2–12 × 8.5–10.8 µm; on different habitats .......................................................................................................................................... E. phaeocyathus