Metacampanella coprophila Burenbaatar Ganbaatar & T. Bau, 2024

Hou, Wei-nan, Ganbaatar, Burenbaatar & Bau, Tolgor, 2024, Two new species of Metacampanella (Agaricales, Marasmiaceae) from China and Mongolia, MycoKeys 108, pp. 227-247 : 227-247

Metacampanella coprophila Burenbaatar Ganbaatar & T. Bau sp. nov.

Figs 2 A, B , 3

Type material.

Holotype. Mongolia • Dornod, Menengiin tal , 8 August 2023, 47 ° 40 ' 28 " N, 116 ° 50 ' 21 " E, alt. 600 m, Tolgor Bau & Burenbaatar Ganbaatar, BH 34 ( FJAU 69317 ).

Etymology.

“ coprophila ” refers to the growth on dung.

Diagnosis.

The pileus is white. The surface is frosted. The stipe is finely scaly, and the base is dark yellowish brown. Basidiospores are ellipsoid. Cheilocystidia two types: tetrapyrgoid, mostly ten pin-shaped. Caulocystidia is long clavate, irregularly curved, smooth.

Description.

Pileus 2–4 mm, bell-shaped when young, then applanate, central protuberance, the surface uneven like a grid pattern after drying, edge slightly involuted, membranous. The surface of the cap is milky white, creamy or beige, rough, frosted scales, the edge complete, wavy, without stripes. The flesh is white and thin. Lamellae white to creamy, distant (L = 12–14, I = 1–2), decurrent. Stipe 4–5 × 0.5–1 mm, cylindrical, upper and lower equal thick, hollow, fibrous, milky white at the top, yellowish white to yellowish brown in the middle, dark yellowish brown, brown to dark brown at the base, and white powdery frosty fine scales on the surface.

Basidiospores 7.8–10.5 × 5–7 μm, Q = 1.5, ellipsoid, the front non-protruding, colorless, smooth, transparent, thin-walled, non-amyloid. Basidia 26–37 × 6–8 μm, clavate, 4 - spored, sometimes 2 - spored, thin-walled, colorless, transparent, clamp connections present at base. Basidioles 25–37 × 4–6.8 μm, rod-shaped or spindle-shaped, thin-walled. Trama hyphae of lamellae irregularity, 3.2–4.6 μm in width, with clamp connections, thick-walled. Cheilocystidia two types: a. tetrapyrgoid, colorless, transparent, thick-walled, 16–21 × 5.7–6.3 µm, clavate or fusiform, an axis beset with numerous diverticula, a swollen obovate apex, smooth, rare; b. mostly ten pin-shaped, phialide or clavate, apex bifurcated or mid-divergent, smooth. Pleurocystidia absent. Terminal cellular elements of pileipellis two types: a. diverticulate repent hypha, 21–30 × 4.7–6.3 µm, light yellow, thick-walled. b. minority tetrapyrgoid, 20–27 × 6.7–7.4 µm, thick-walled. Pileipellis composed of extremely tightly interwoven hyphae, 4–6.9 µm in width, pale yellow, transparent, thick-walled. Caulocystidia 19–30 × 4.8–8 µm, phialide or clavate, irregularly curved, yellow, thick-walled, smooth. Stipitipellis cylindrical, 4.2–5.9 µm in width, parallel, yellow, thick-walled. Trama hyphae of stipe cylindrical, 6–8 µm in width, parallel, colorless, transparent, thick-walled. Clamp connections present in all tissues.

Habitat and distribution.

Summer-growing, in sheep dung. Currently only known from Mongolia.

Additional specimens examined.

Mongolia • Dornod, Menengiin tal , 8 August 2023, 47 ° 40 ' 28 " N, 116 ° 50 ' 20 " E, Tolgor Bau, Haiying Bao and Burenbaatar Ganbaatar, B 34 ( FJAU 69316 ) .

Notes.

This species is similar to Metacampanella subtricolor in terms of morphological characteristics. However, cheilocystidia of Metacampanella coprophila is two types: a. tetrapyrgoid, b. mostly ten pin-shaped and caulocystidia only phialide or clavate. Nevertheless cheilocystidia of Metacampanella subtricolor is only tetrapyrgoid and caulocystidia two types: a. tetrapyrgoid, b. individual arboreal dermatocystidia. At the same time, the habitat of Metacampanella coprophila is special for sheep dung.

Figures

Figure 2. Basidiomata A, B Metacampanella coprophila C, D Metacampanella subtricolor E, F Metacampanella tricolor. Scale bars: 5 mm.

Figure 3. Metacampanella coprophila A basidiomata B basidiospores C basidia D basidioles E cheilocystidia F pileipellis G stipitipellis. Scale bars: 1 mm (A); 5 µm (B); 15 µm (C – G).