Ceraceomyces rhizomorphus C. L. Zhao & H. M. Zhou, 2024

Zhou, Hong-Min, Zhang, Xun-Chi, Li, Jie-Ting, Wu, Fang & Zhao, Chang-Lin, 2024, Morphological characteristics and phylogenetic analyses revealed four new wood inhabiting fungi (Agaricomycetes, Basidiomycota) in Xizang Autonomous Region, China, MycoKeys 106, pp. 201-224 : 201-224

Ceraceomyces rhizomorphus C. L. Zhao & H. M. Zhou sp. nov.

Figs 7 , 8

Holotype.

China, Xizang, Linzhi, Sejilashan National Forest Park , 29 ° 64 ' N, 94 ° 71 ' E, elev. 3848 m, on the fallen branch of Abies , 2 August 2023, CLZhao 31188 ( SWFC).

Etymology.

Rhizomorphus (Lat.): refers to the basidiomata with rhizomorphs.

Diagnosis.

Differed from other species in having merulioid, cream to yellowish basidiomata, generative hyphae with clamp connections, cylindrical basidiospores (4.7–6.2 × 1.8–2.3 µm).

Fruiting body.

Basidiomata resupinate, adnate, smooth to tuberculate when fresh, merulioid upon drying, without odor or taste when fresh, up to 6 cm long, 2 cm wide, 100–200 µm thick. Hymenial surface merulioid, cream to yellowish when fresh, turn to orange yellow upon drying. Margin sterile, white, with rhizomorphs.

Hyphal structure.

Hyphal system monomitic, generative hyphae with clamp connections, colorless, thin- to slightly thick-walled, branched, interwoven, 3.5–7 µm in diameter, IKI –, CB –; tissues turn black in KOH.

Hymenium.

Cystidia and cystidioles absent; basidia narrowly clavate to clavate, in a dense palisade, with 4 sterigmata and a basal clamp connection, 16–19 × 3.5–4 µm; basidioles dominant, similar to basidia in shape, but slightly smaller.

Spores.

Basidiospores cylindrical, with suprahilar depression, colorless, smooth, thin-walled, IKI –, CB –, (4.2 –) 4.7–6.2 (– 6.4) × (1.5 –) 1.8–2.3 (– 2.4) µm, L = 5.49 µm, W = 2.05 µm, Q = 2.66–2.68 (n = 60 / 2).

Additional specimens examined

(paratypes). China. Xizang, Linzhi, Sejila Mountain National Forest Park , 29 ° 64 ' N, 94 ° 71 ' E, elev. 3848 m, on the trunk of Abies , 2 August 2023, CLZhao 31153 ( SWFC) ; CLZhao 31154 ( SWFC) ; CLZhao 31161 ( SWFC) ; CLZhao 31202 ( SWFC) ; on the fallen branch of Abies , 2 August 2023, CLZhao 31184 ( SWFC) ; CLZhao 31185 ( SWFC) ; CLZhao 31197 ( SWFC) .

Figures

Figure 7. Basidiomata of Ceraceomyces rhizomorphus A, C CLZhao 31188 (holotype) B, D CLZhao 31185.

Figure 8. Microscopic structures of Ceraceomyces rhizomorphus (holotype, CLZhao 31216) a basidiospores b basidia c basidioles d a section of hymenium. Scale bars: 5 μm (a); 10 μm (b – d).