Entoloma rubropilosum Xiao L. He & E. Horak

He, Xiao-Lan, Horak, Egon, Wang, Di, Peng, Wei-Hong & Gan, Bing-Cheng, 2018, Three new species of EntolomasubgenusPouzarella from China based on morphological and molecular data, MycoKeys 44, pp. 1-18 : 1

publication ID

https://dx.doi.org/10.3897/mycokeys.44.24998

persistent identifier

https://treatment.plazi.org/id/5AE3A98A-E0EC-A1DF-CEBC-94592414FD51

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MycoKeys by Pensoft

scientific name

Entoloma rubropilosum Xiao L. He & E. Horak
status

sp. nov.

Entoloma rubropilosum Xiao L. He & E. Horak sp. nov. Figs 1e, f, 4

Diagnosis.

E. rubropilosum is distinct due to its reddish-brown coloured pileus and stipe, large basidiospores (13-17 × 7.5-9.5 µm), broadly clavate cheilocystidia, distinctive thick-walled setiform caulocystidia and terminal cells of the pileipellis hyphae.

Type.

CHINA: SICHUAN PROV.: Yajiang County, Gexigou National Nature Reserve, 29°33'N, 100°50'E, elevation ca. 2950 m, 24 July 2013, He X.L. (SAAS 406, holotype).

Etymology.

Rubropilosum, refers to the reddish coloured fibrils on the pileus.

Description.

Pileus 7-20 mm broad, conical-convex, truncate conical to broadly campanulate, dark reddish-brown (8D2-8D3) at first, becoming greyish-orange to pale beige brownish (5B2-5C2), dry, slightly hygrophanous, densely covered by reddish-brown erect or suberect squamules and fibrils; fibrils much denser at disc, margin not striate or very slightly striate only. Lamellae adnate to sinuate, ventricose, up to 2.5 mm wide, relatively thick, with two tiers of lamellulae, brownish-pink when mature, with concolorous and entire edges. Stipe 40-73 × 0.8-2 mm, central, cylindrical, hollow, densely covered with rust reddish hairs or fibrils, very dark brown strigose at base. Odour and taste not distinctive.

Basidiospores (12.5-) 13-17 × 7.5-9.5 µm (x = 15.2 ± 0.5 × 8.5 ± 0.3 µm), Q = 1.53-1.98 (Q = 1.76 ± 0.02), heterodiametrical, with 6-8 facets in profile and face views, sometimes multi-angled to nodulose, pale brownish, thick-walled. Basidia (32-) 38-45 (-50) × 12-16 µm, clavate, 4-spored. Aborted basidia inconspicuous. Lamellar edges sterile. Cheilocystidia 25-50 × 12-18 µm, broadly clavate, with faintly pale brownish, intracellular pigment, slightly thick-walled. Pleurocystidia absent. Pileipellis a trichoderm composed of brown hyphae; terminal cells 23-110 × 6-18 µm (diameter was measured at the base), slender setiform, gradually tapering towards subacute apex, sometimes subfusoid to somewhat bullet-shaped, thick-walled, with intraparietal and intracellular brown pigment; subpellis composed of cylindrical, relatively thin-walled hyphae, encrusted with yellow-brown pigment. Stipitipellis composed of loosely entangled, rather slender hyphae; terminal cells 45-120 × 5-11 µm (diameter was measured at the base), distinctly setiform with obtuse or subacute apex, thick-walled, with intraparietal and intracellular brown pigment. Oleiferous hyphae absent. Clamp connections absent.

Habitat.

Scattered on soil amongst decaying litter in broadleaf forest dominated by Quercus or in mixed forest with Quercus , Betula , Rhododendron and Abies , also on soil in bamboo forest.

Additional collections examined.

CHINA. SICHUAN PROV.: Yajiang County, Gexigou National Nature Reserve, 29°33'N, 100°50'E, elevation ca. 2950 m, 24 July 2013, He X.L. (SAAS 765); 24 July 2013, He X.L. (SAAS 706); 3 August 2014, He X.L. (SAAS 1488, SAAS 1112, ZT 14179). TIBET: Linzhi, Lulang, 29°94'N, 94°79'E, elevation ca. 3800 m, 18 September 2014, He X.L. (SAAS 1618, SAAS 1087); Linzhi, Kadinggou, 29°50'N, 93°26'E, elevation ca. 2950 m, 24 September 2014, He X.L. (SAAS 1456).

Comments.

The setiform terminal cells of pileipellis and stipitipellis place E. rubropilosum in sect. Pouzarella . It is readily recognised in the field. A few species of Entoloma subgen. Pouzarella with reddish-brown fibrils or squamules have been reported in literature ( Mazzer 1976; Baroni et al. 2008). E. ferreri (T.J. Baroni, Perd.- Sánch. & S.A. Cantrell) Noordel. & Co-David is distinguished by dark blackish stains on the pileus caused from handling and non-setiform pileocystidia and caulocystidia ( Baroni et al. 2008). E. strigosissimum (Rea) Noordel. is separated by the larger basidiospores [15-19 (23) × 8.5-10.5 (11.5) µm, Mazzer 1976]. E. squamifolium (Murrill) Singer might be confused with E. rubropilosum due to the ferruginous hairs on the stipe ( Mazzer 1976). However, E. rubropilosum can be distinguished by the setiform pileocystidia and caulocystidia. Furthermore, type of E. squamifolium was collected in a tropical location. The recently described E. wayanadense K. N. A. Raj & Manim. from India, also discovered in a tropical area, is similar to E. rubropilosum in its greyish-orange pileus with long hairs and the setiform terminal cells of pileipellis, but differs by the absence of cheilocystidia. In addition, the partial ITS sequence (419 bp, KY 643748) of E. wayanadense is quite different from that of E. rubropilosum ( Raj and Manimohan 2017).