Entoloma griseopileum M. Q. He & X. Liu, 2025

Entoloma griseopileum M. Q. He & X. Liu sp. nov.

Fig. 4 View Figure 4

Etymology.

the epithet “ griseo ” means gray, the name refers to the grayish pileus.

Holotype.

China • Qinghai Province Mutual Aid County, Beishan National Forest Park, Langshidang , 10 July 2023, MQ He, ZRL 20230583 ( HMAS 300884 View Materials ).

Diagnosis.

This species is characterized by its gray basidiomes and fibrillose pileus.

Original description.

Pileus is 26–32 mm in diameter, broadly convex, umbonate on the disc, margin slightly decurved when young, getting straight or slightly uplifted when mature; surface dry, fibrillose, background gray, fibrils light brown, denser and darker on the disc. Lamellae up to 3 mm broad, adnate or slightly sinuate, eroded, white, slightly pink, getting brown or dark brown near the pileus edge. Stipe 33.53–42.20 × 3.2–3.5 mm, concolor with the pileus, darker toward base, cylindrical, equal, surface dry, smooth, silky, occasionally with the same fibrils as on pileus.

Basidiospores 6.8–10.1 × 5.9–7.7 μm [x ̄ = 8.9 ± 0.7 × 6.7 ± 0.4 μm, Q = 1.0–1.6, Q m = 1.3 ± 0.1, n = 20], heterodiametric, with 5–7 angles in side-view. Basidia 31.8–40.6 × 9.3–13.8 μm, 4 - spored. Cheilocystidia absent. Pileipellis a cutis with a transition to a plagiotrichoderm and a trichoderm of cylindrical to slightly inflated hyphae 4.6–11.1 μm wide, with membranous brown pigment. Clamp connections absent. Lamellae edge is fertile.

Habitat.

Wood-inhabiting.

Notes.

Morphologically, E. griseopileum resembles E. bisporigerum in the field which also can be found in northern China ( Li et al. 2015). Both species have grayish small basidiomes (pileus smaller than 4 cm in diameter). But under microscope, E. bisporigerum can be distinguished from E. griseopileum by its larger basidiospores (11.5–13.5 × 7.5–9 μm). Furthermore, E. bisporigerum grows on soil, while E. griseopileum grows on wood.

Other specimens examined.

China • Qinghai Province, Beishan National Forest Park, Langshidang , 10 July 2023, MQ He, ZRL 20230545 ( HMAS 300885 View Materials ), ZRL 20230575 ( HMAS 300883 View Materials ) .