Mycena brunneocystidiata J. W. Guo, Z. W. Liu, Y. P. Ge & Q. Na, 2025

Guo, Jingwen, Liu, Zewei, Zeng, Hui, Ge, Yupeng & Na, Qin, 2025, Three new species of Mycena sect. Calodontes (Mycenaceae, Agaricales) from Northeastern China, MycoKeys 125, pp. 51-79 : 51-79

Mycena brunneocystidiata J. W. Guo, Z. W. Liu, Y. P. Ge & Q. Na sp. nov.

Figs 2 , 3 , 4 , 5

Diagnosis.

Pileus brown. Lamellae densely covered with dark brown dots, margin brown. Cheilocystidia, pleurocystidia, caulocystidia and terminal cells of stipitipellis with brownish contents. Differ from M. lammiensis by wider basidiospores (width> 4 μm) and fusiform caulocystidia.

Holotype.

China • Heilongjiang Province, Mudanjiang City, Mudanfeng National Forest Park, 42 ° 45 ' 74 " N, 128 ° 14 ' 41 " E, 22 August 2024, Jingwen Guo, Tian Wang, Qin Na, Zengcai Liu, Ruipeng Liu, Pengyu Du, Ying Yu, and Yupeng Ge leg., FFAAS 3400 (collection no. NJ 6538 ).

Etymology.

Name refers to the cheilocystidia, pleurocystidia, and caulocystidia with brown contents.

Description.

Pileus 10–36 mm in diam., plano-convex, with slightly umbo at center, margin revolute, wavy, cracked at mature; * Drab ( XLVI 17 ′′′′) at center, gradually towards margin to PaMid Vinaceous-Drab ( XLV 5 ′′′′ f), Pale Drab-Gray ( XLVI 17 ′′′′ f) to * Drab-Gray ( XLVI 17 ′′′′ d), margin * Drab ( XLVI 17 ′′′′); striate * Hair Brown ( XLVI 17 ′′′′ i), towards the center up to 1 / 2–2 / 3 diam .. Context White ( LIII), 1.0 mm thick, fragile. Lamellae subdecurrent, 23–27 reaching the stipe, 1–3 tiers of lamellulae, White ( LIII), densely covered with Deep Brownish Drab ( XLV 9 ′′′′ i) dots, irregularly intervenose, stretching downward to 2 / 3–3 / 4 of the width of lamellae, edge entirely Deep Brownish Drab ( XLV 9 ′′′′ i), wavy. Stipe 24–44 × 2–4 mm, central, cylindrical; apex to middle * Smoke Gray ( XLVI 21 ′′′′ d) to Pale Smoke Gray ( XLVI 21 ′′′′ f), base * Ecru-Drab ( XLVI 13 ′′′′ d) to * Drab-Gray ( XLVI 17 ′′′′ d), hollow, fragile, apex with Light Drab ( XLVI 17 ′′′′ b) to * Drab ( XLVI 17 ′′′′) striates, sparse White ( LIII) pubescent at base. Odor and taste not distinctive.

Basidiospores (60 / 3 / 2) (5.4) 5.6– 6.3 – 6.9 (7.1) × (2.6) 2.9– 3.2 – 3.5 (4.0) μm [ Q = (1.72) 1.77–2.16 (2.19), Q m = 1.97 ± 0.09] [ holotype (40 / 2 / 1) 6.0– 6.5 – 6.9 (7.1) × 3.0– 3.2 – 3.5 μm [ Q = (1.83) 1.89–2.15 (2.18), Q m = 2.00 ± 0.08], narrowly ellipsoid to cylindrical, colorless, smooth (1000 ×), thin-walled, amyloid. Basidia clavate, 16–21 × 5–7 μm, hyaline, thin-walled, 4 - spored, sterigmata 2–3 μm in length. Cheilocystidia fusiform with tapered apices, 36–62 × 9–14 μm (Fig. 3 G – J , Fig. 4 D 1 ), acicular to lanceolate, 46–84 × 10–17 μm (Fig. 3 M – P , Fig. 4 D 2 ), with brownish contents, thin-walled, smooth. Pleurocystidia similar to cheilocystidia, 39–72 × 8–15 μm, with brownish contents, thin-walled, smooth. Pileipellis a cutis composed of cylindrical cells, 32–121 × 3–6 μm, smooth, thin-walled; terminal cells cylindrical, apex tapering, 34–87 μm in length, apex 1–3 μm, base 3–7 μm, thin-walled, hyaline. Hypodermium formed by fusiform to subglobose hyphae, 20–72 × 12–39 μm, thin-walled, hyaline. Lamellar trama subregular, dextrinoid. Stipitipellis a cutis composed of cylindrical hyphae, 9–18 μm in diam., smooth, thin-walled; terminal cells fusiform or cylindrical, apex tapering, 31–72 × 4–8 μm, with pale brownish contents, thin-walled, smooth; caulocystidia fusiform, 33–70 × 7–13 μm, with pale brownish contents, thin-walled, smooth. Clamps present in all tissues.

Habit and habitat.

Scattered on the litter layer in Acer mono Maxim. , Larix gmelinii (Ruprecht) Kuzeneva , Pinus koraiensis Siebold et Zuccarini , and Quercus mongolica Fischer ex Ledebour mixed forests during summer and autumn.

Known distribution.

Heilongjiang Province, Jilin Province, China.

Additional material examined.

China • Jilin Province, Yanbian Korean Autonomous Prefecture, Antu County, Erdaobaihe Town , Back Mountain of Changbai Mountain Natural History Museum , 42 ° 46 ' 43 " N, 128 ° 14 ' 49 " E, 17 August 2021, Zewei Liu, Qin Na, Shixin Wang, and Yupeng Ge leg., FFAAS 3401 (collection no. MY 0611 ) .

Notes.

Mycena brunneocystidiata is considered to be a distinct species of sect. Calodontes subsect. Marginatae J. E. Lange on account of its lamellae margins brown and cheilocystidia, pleurocystidia, and caulocystidia with brown contents ( Maas Geesteranus 1992 a, 1992 b). In the subsection, M. lammiensis and M. pelianthina share the same colored lamellae margins, cheilocystidia, and pleurocystidia with purple-brown contents, but M. lammiensis differs in having larger basidiospores (7.5–9.0 × 4.0–5.0 μm) and cylindrical caulocystidia, while M. pelianthina is identified by purple-brown pileus and lacking caulocystidia ( Harmaja 1985; Robich 2003; Harder et al. 2010; Aronsen and Læssøe 2016). Mycena shengshanensis resembles M. brunneocystidiata in growing on the humus layer of Larix gmelinii and having light purple-brown to brown pileus, but differs in colorless, clavate, and thick-walled cheilocystidia ( Liu et al. 2022).

The main shape of cheilocystidia and pleurocystidia in FFAAS 3401 is fusiform with tapered apices (Fig. 5 A – E, K – O ), but in specimen FFAAS 3400, acicular to lanceolate cheilocystidia and pleurocystidia can be observed occasionally, which are larger than the fusiform ones (Fig. 5 F – J, P – T ).

Figures

Figure 2. Basidiomata of Mycena brunneocystidiata. A – D. Collection FFAAS 3400, holotype; E – I. Collection FFAAS 3401. Scale bars: 20 mm (A – B, E, G – H); 1 mm (C, F); 5 mm (D, I). Photographs (A – I) by Jingwen Guo and Yupeng Ge.

Figure 3. Microscopic features of Mycena brunneocystidiata (FFAAS 3400, holotype). A – E. Basidiospores; F. Basidia; G – J. Fusiform cheilocystidia; K – L. Acicular to lanceolate cheilocystidia; M – P. Fusiform pleurocystidia; Q – R. Acicular to lanceolate pleurocystidia; S. Pileipellis and hypodermium; T. Lamellar trama; U. Stipitipellis and caulocystidia. Scale bars: 5 μm (A – E); 10 μm (F); 25 μm (G – R); 20 μm (S – U). Structures (A – E) were rehydrated in 5 % KOH aqueous solution, (G – R, U) were rehydrated in sterile water and (F, S – T) were stained in 1 % Congo red aqueous solution.

Figure 4. Morphological features of Mycena brunneocystidiata (FFAAS 3400, holotype). A. Basidiomata; B. Basidiospores; C. Basidia; D 1. Fusiform cheilocystidia; D 2. Acicular to lanceolate cheilocystidia; E 1. Fusiform pleurocystidia; E 2. Acicular to lanceolate pleurocystidia; F. Stipitipellis and caulocystidia; G. Pileipellis and hypodermium. Scale bars: 20 mm (A); 5 μm (B); 10 μm (C); 25 μm (D 1 – G). Drawings by Jingwen Guo.

Figure 5. Morphological features of the Cheilocystidia and pleurocystidia of Mycena brunneocystidiata. A – E. Cheilocystidia of FFAAS 3401; F – J. Cheilocystidia of FFAAS 3400, holotype; K – O. Pleurocystidia of FFAAS 3401; P – T. Pleurocystidia of FFAAS 3400, holotype. Scale bars: 25 μm (A – E, K – O); 30 μm (F – J, P – T). Drawings by Jingwen Guo.