Peniophorella subreticulata Xue W. Wang & L.W. Zhou, sp. nov.

Index Fungorum number: IF 900288; Mycobank number: MB 900288; Facesoffungi number: FoF 14050; Figs. 1, 2

Etymology – subreticulata (Lat.) referring to the similarity to P. reticulata.

Holotype – LWZ 20200921-49b (HMAS).

Diagnosis – Characterized by annual, resupinate, basidiomes, grandinioid to odontioid, white to cream hymenophore, a monomitic hyphal system, embedded, fusoid to subcylindrical leptocystidia and subcylindrical asterocystidia, the presence of stephanocysts, and ellipsoid to oblong basidiospores.

Basidiomes annual, resupinate, adnate, ceraceous, without odour or taste when fresh, becoming cracked upon drying. Hymenophore grandinioid to odontioid, white to cream when fresh, turn to cream upon drying, margin abrupt.

Hyphal system monomitic; generative hyphae with clamp connections, hyaline. Subicular hyphae thin-walled, 4–5 μm in diam. Subhymenial hyphae thin- to slightly thick-walled, occasionally encrusted with granules, moderately branched, 4.5–5.5 μm in diam. Stephanocysts present in subhymenium. Cystidia two types: 1) leptocystidia scattered, embedded in subhymenium and hymenium, fusoid to subcylindrical, thin-walled, often with granules on the surface, 45–50×9–10 μm; 2) asterocystidia subcylindrical, thickwalled, 15–35 × 4–5.5 μm. Large solitary of aggregated crystals occurring in lower subhymenium and between hyphae in peg-like projections. Basidia clavate, thin-walled, smooth, with four sterigmata and a basal clamp connection, 15–20×7.5–8 μm; basidioles in shape similar to basidia but slightly smaller. Basidiospores narrowly ellipsoid to oblong with flat or slightly concave adaxial side, thin-walled, IKI–, CB–, (7.5–)7.8–9.3(–10.3)×3.8–4.7(–5.1) μm, L=8.51 μm, W=4.33 μm, Q=1.95–1.99 (n=90/3).

Material examined – China, Sichuan Province, Liangshan Yi Autonomous Prefecture, Leibo County, Mamize Nature Reserve, on fallen branch of gymnosperm, 21 September 2020, L.W. Zhou, LWZ 20200921-49b (HMAS, holotype); ibid., on fallen trunk of Picea, 21 September 2020, L.W. Zhou, LWZ 20200921-61a (HMAS); Liangshan Yi autonomous prefecture, Meigu County, Dafengding National Nature Reserve, on fallen branch of Cryptomeria fortunei, 18 August 2019, L.W. Zhou, LWZ 20190818-35b (HMAS); Ganzi Tibetan Autonomous Prefecture, Jiulong County, Wuxuhai Scenic Spot, on fallen trunk of Picea, 13 September 2019, L.W. Zhou, LWZ 20190913–21 (HMAS); ibid., on fallen branch of Picea, 12 August 2020, L.W. Zhou, LWZ 20200812-37a (HMAS).

GenBank numbers – LWZ 20200921-49b: ITS=OQ540884; LSU=OQ540845; LWZ 20200921-61a: ITS= OQ540885; 20190818-35b: ITS= OQ540887; LWZ 20190913–21: ITS=OQ540888; LSU=OQ540847; LWZ 20200812-37a: ITS=OQ540886; LSU=OQ540846.

Notes – Peniophorella reticulata phylogenetically groups with P. subreticulata. Morphologically, P. reticulata differs in wider basidiospores (5–6 μm in width, Q=1.5–1.7), and the absence of stephanocysts and asterocystidia (Yurchenko et al. 2020).

Figure 1 – Basidiomes of Peniophorella subreticulata (LWZ 20200921-49b, holotype)

Figure 2 – Microscopic structures of Peniophorella subreticulata (LWZ 20200921-49b, holotype). a Basidiospores b Basidia and basidioles c Leptocystidia d Hyphidia e Section through a basidiomes. Scale bars: a–e=10 μm