Mycena subulata Z.W. Liu, Y.P. Ge & Q. Na, sp. nov.

Liu, Zewei, Ge, Yupeng, Zeng, Hui, Cheng, Xianhao & Na, Qin, 2022, Four new species of Mycena sect. Calodontes (Agaricales, Mycenaceae) from northeast China, MycoKeys 93, pp. 23-56 : 23

Mycena subulata Z.W. Liu, Y.P. Ge & Q. Na, sp. nov.

Figs 13 , 14 , 15

Diagnosis.

Pileus reddish-grey to dull red, slightly hygrophanous. Cheilocystidia thick-walled, slenderly fusiform with distinctly long and narrow protuberance. Stipitipellis a cutis, with projecting hyphae, caulocystidia thick-walled.

Holotype.

China. Heilongjiang Province: Liangshui National Nature Reserve, Yichun City, 47°13'13"N, 128°53'21"E, 21 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0423 (collection number MY0671).

Etymology.

Refers to cheilocystidia with distinctly long and narrow protuberance.

Description.

Pileus 9-32 mm in diam., convex to campanulate when young, hemispherical to applanate with age, margin sometimes wavy, slightly deflexed; at centre dull red (8C3), brownish-grey (8D2), greyish-brown (8D3), reddish-brown (8D4, 8E4-8E5) and dark brown (8F5), disc paler to reddish-grey (8B2, 9B2), brownish-grey (9C2), dull red (9B3, 9C3), greyish-magenta (13D3), margin light brown (7D4), brown (7E4) or dull red (9C3); striate none or indistinct, reddish-brown (8E4-8E5), towards the centre up to 1/5 diam.; surface dry, unclearly rugose or none, margin slightly hygrophanous. Context white, 1 mm thick, fragile. Lamellae sinuate to subdecurrent, 31-33 reaching the stipe, 1-3 tiers of lamellulae, white, irregularly intervenose, edge concolorous, wavy and slightly serrulate. Stipe 27-75 × 2-5 mm, central, cylindrical, apex to middle brownish-orange (7C3), dull red (8C3), brownish-grey (7D2), greyish-magenta (14D3), lower part brownish-grey (8C2), greyish-brown (8D3), reddish-brown (8D4), fragile, hollow, white granular near apex, base slightly swollen with white fibrils. Odour raphanoid, taste indistinct.

Basidiospores (100/5/4) 6.0-6.7-7.3(7.9) × 3.3-3.8-4.3(4.6) μm [Q = (1.61)1.65-1.87(1.90), Q = 1.76 ± 0.07] [holotype (40/2/1) (6.0)6.2-6.6-7.1 × 3.4-3.7-4.0(4.2) μm, Q = 1.65-1.87(1.90), Q = 1.78 ± 0.07], elongated ellipsoid, colourless, smooth, thin-walled, amyloid. Basidia 23-34 × 5-6 μm, 4-spored, clavate, hyaline, sterigmata 2-3 μm in length. Cheilocystidia moderately thick-walled (0.5-0.6 μm), hyaline, narrowly fusiform with long and narrow protuberance, 43-82 × 4-11 μm, protuberance 14-36 × 1-2 μm. Pleurocystidia absent. Pileipellis a cutis composed of three to four layers of cylindrical cells, 20-89 × 3-7 μm, smooth and thin-walled; terminal cells cylindrical, apically narrow, 24-61 μm in length, the apex 3-4 μm and base 4-7 μm in diam., thin-walled, hyaline. Hypodermium formed by fusiform to subglobose hyphae, 21-41 × 17-25 μm, thin-walled, hyaline. Lamellar trama subregular, dextrinoid. Stipitipellis a cutis composed of hyphae 3-8 μm in diam., smooth, thin-walled, with projecting hyphae 3-8 μm in diam.; caulocystidia 29-47 × 6-12 μm, clavate and apices tapered, thick-walled (0.5-0.6 μm), smooth. Clamps present in all tissues.

Habitat.

Scattered on the litter layer in Pinus koraiensis , Larix gmelinii and Tilia sp. mixed forests.

Known distribution.

Heilongjiang Province, China.

Additional material examined.

China. Heilongjiang Province: Liangshui National Nature Reserve, Yichun City , 21 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0419 (collection number MY0654); same location, 21 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0420 (collection number MY0657) ; Heilongjiang Province: Taipinggou National Nature Reserve, Hegang City , 3 September 2021, Shixin Wang, FFAAS0426 (collection number MY0795) .

Notes.

Cheilocystidia with a long and narrow protuberance is the key microscopic character that distinguishes M. subulata and is uncommon in sect. Mycena Calodontes ( Smith 1947; Maas Geesteranus 1992a, 1992b; Grgurinovic 2003; Robich 2003; Chew et al. 2014; Aravindakshan and Manimohan 2015; Aronsen and Læssøe 2016; Na 2019; Liu et al. 2021). Mycena lammiensis Harmaja and M. pelianthina (Fr.) Quél. have similar cheilocystidia, but differ from M. subulata by their broader cheilocystidia with purplish-brown contents and having pleurocystidia ( Smith 1947; Robich 2003; Aronsen and Læssøe 2016). The cheilocystidia of M. subcorticalis (Cooke & Massee) Sacc. with a protuberance are similar to those of M. subulata . However, M. subcorticalis has larger and inamyloid spores, a gelatinised pileipellis and a stipitipellis with sparse excrescences ( Grgurinovic 2003). More rarely, mucronate cheilocystidia and absence of pleurocystidia have been described for M. pearsoniana and its clay pink pileus is similar to that of M. subulata , but M. pearsoniana differs in having a slightly glutinous pileus when wet and inamyloid spores ( Aronsen and Læssøe 2016; Na 2019). Other species that are macroscopically similar to M. subulata , namely M. luteovariegata , M. nullawarrensis and M. pura , can be distinguished by cheilocystidia shape and presence of pleurocystidia ( Perry 2002; Robich 2003; Grgurinovic 2003; Harder et al. 2013; Aronsen and Læssøe 2016; Na 2019).

Figures

Figure 13. Basidiomata of Mycena subulata Z. W. Liu, Y. P. Ge & Q. Na a, b FFAAS 0419 c, d FFAAS 0420 e-g FFAAS 0423, holotype h FFAAS 0426 Scale bars: 10 mm (a-h). Photographs a, b, e, f by Yupeng Ge c, d by Qin Na g by Zewei Liu h by Shixin Wang.

Figure 14. Microscopic features of Mycena subulata (FFAAS 0423, holotype) a-e basidiospores f basidia g-m cheilocystidia n lamellar trama o pileipellis and hypodermium p stipitipellis and caulocystidia. Scale bars: 5 μm (a-e); 10 μm (f); 20 μm (g-p).

Figure 15. Morphological features of Mycena subulata (FFAAS 0423, holotype) a basidiomata b basidia c basidiospores d cheilocystidia e stipitipellis and caulocystidia f pileipellis and hypodermium. Scale bars: 10 mm (a); 5 μm (c); 10 μm (b, d-f). Drawings by Zewei Liu.