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

Figs 9 , 10 , 11 , 12

Diagnosis.

Pileus brown to violet-brown at centre, disc light brown to dull red. Cheilocystidia clavate with slightly inflated apex, thick-walled. Pleurocystidia absent. Caulocystidia clavate with tapered apices, apex to middle thick-walled. Scattered to gregarious under Larix gmelinii .

Holotype.

China. Heilongjiang Province: Shengshan National Nature Reserve, Heihe City, 49°37'45"N, 126°47'39"E, 23 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0424 (collection number MY0686).

Etymology.

Refers to the type locality.

Description.

Pileus 13-26 mm in diam., when young parabolic to convex, with obtuse umbo at centre, then plano-convex, margin wavy and revolute, at times cracked at mature; centre light brown (7D5-7D6), brown (7E4-7E8), dark brown (8F5-8F6), violet brown (11F4-11F6), disc paler to light brown (7D4-7D5), brown (7E5-7E6), greyish-brown (8D3), reddish-brown (8D4, 8E4), brownish-grey (11C2), dull red (11C3), margin whitish; striate indistinct, brownish-orange (7C3), greyish-brown (7D3), reddish-grey (12D2), greyish-ruby (12E3-12E5), towards the centre up to 1/3-1/2 diam.; surface slightly moist, smooth. Context white, 1-2 mm thick, fragile. Lamellae sinuate to subdecurrent, 19-25 reaching the stipe, 1-3 tiers of lamellulae, white, irregularly intervenose, edge concolorous, wavy and slightly serrulate. Stipe 26-42 × 2-4 mm, central, cylindrical, apex reddish-brown (8E4-8E5), greyish-ruby (12E4-12E5), greyish-brown (11F3), violet brown (11F4-11F5), dark ruby (12F4-12F5), lower part paler to brownish-grey (7C2), brownish-orange (7C3), greyish-brown (11E3), greyish-ruby (12E3), base darker to brown (7E5), reddish-brown (8E4-8E5), greyish-brown (11F3), violet brown (11F4-11F5), greyish-ruby (12E3), dark ruby (12F6-12F8), fragile, hollow, base swollen with white fibrils. Odour raphanoid, taste indistinct.

Basidiospores (60/3/2) (5.9)6.1-6.9-8.1(8.7) × 3.4-4.0-4.4(4.7) μm [Q = 1.62-1.93 (1.97), Q = 1.75 ± 0.09] [holotype (40/2/1) 6.1-7.0-8.2(8.7) × 3.4-4.0-4.4(4.7) μm, Q = (1.62)1.65-1.93(1.97), Q = 1.77 ± 0.08], elongated ellipsoid, colourless, smooth, thin-walled, amyloid. Basidia 22-32 × 6-8 μm, 4-spored, clavate, hyaline, sterigmata 3-4 μm in length. Cheilocystidia moderately thick-walled (0.5-0.6 μm), clavate with slightly inflated apex, 25-63 × 6-12 μm, hyaline. Pleurocystidia absent. Pileipellis a cutis composed of three to four layers of cylindrical cells, 24-57 × 3-5 μm, smooth and thin-walled; terminal cells cylindrical, apically narrow, 28-49 μm in length, apex 1-3 μm and base 2-5 μm in diam., thin-walled, hyaline. Hypodermium formed by fusiform to subglobose hyphae, 19-53 × 13-30 μm, thin-walled, hyaline. Lamellar trama subregular, weakly dextrinoid to dextrinoid. Stipitipellis a cutis composed of hyphae 4-9 μm in diam., smooth, thin-walled; caulocystidia 22-61 × 5-20 μm, clavate with tapered apices, apex to middle thick-walled, smooth, hyaline. Clamps present in all tissues.

Habitat.

Scattered to gregarious on the litter layer in Larix gmelinii .

Known distribution.

Heilongjiang Province, China.

Additional material examined.

China. Heilongjiang Province: Shengshan National Nature Reserve, Heihe City , 23 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0425 (collection number MY0687) .

Notes.

In sect. Mycena Calodontes , M. diosma , M. pearsoniana and M. yuezhuoi also have clavate cheilocystidia with a slightly inflated apex and lack pleurocystidia, similar to M. shengshanensis , but M. diosma differs in pileus characters, M. pearsoniana has inamyloid spores and M. yuezhuoi has a more purple pileus and subcellular lamellar trama ( Robich 2003; Aronsen and Læssøe 2016; Na 2019; Liu et al. 2021). Clavate cheilocystidia are also present in M. luteovariegata and M. pura , but these species differ in having pleurocystidia ( Perry 2002; Robich 2003; Harder et al. 2013; Aronsen and Læssøe 2016; Na 2019). Macroscopically, several species in sect. Mycena Calodontes also have a brown with reddish or violet pileus or stipe ( Smith 1947; Maas Geesteranus 1992a, 1992b; Grgurinovic 2003; Robich 2003; Aronsen and Læssøe 2016). Mycena dura , M. kuehneriana and M. nullawarrensis are distinguished by basidiospore size ( Smith 1947; Maas Geesteranus 1992a, 1992b; Grgurinovic 2003; Robich 2003; Aronsen and Læssøe 2016). Two species, M. seminau and M. sirayuktha , reported from Southeast Asia, are similar to M. shengshanensis owing to the brown pileus, but they differ in having gelatinised or sometimes mucronate cheilocystidia and caulocystidia have not been observed ( Chew et al. 2014; Aravindakshan and Manimohan 2015). Fusiform, obclavate, ovate and clavate cheilocystidia with a subcapitate protuberance were observed occasionally, but clavate cheilocystidia with a slightly inflated apex represented the predominant morphological type in M. shengshanensis (Fig. 12 ).

Figures

Figure 9. Basidiomata of Mycena shengshanensis Z. W. Liu, Y. P. Ge & Q. Na a-d FFAAS 0424, holotype e-h FFAAS 0425 Scale bars: 10 mm (a-h). Photographs a-c, e-g by Yupeng Ge d, h by Zewei Liu.

Figure 10. Microscopic features of Mycena shengshanensis (FFAAS 0424, holotype) a-e basidiospores f basidia g-r cheilocystidia s lamellar trama t pileipellis and hypodermium u stipitipellis and caulocystidia. Scale bars: 5 μm (a-e); 20 μm (g-r); 40 μm (s-u).

Figure 11. Morphological features of Mycena shengshanensis (FFAAS 0424, holotype) a basidiomata b basidia c basidiospores d cheilocystidia e stipitipellis and caulocystidia f pileipellis and hypodermium. Scale bars: 10 mm (a); 10 μm (b-f). Drawings by Zewei Liu.

Figure 12. Cheilocystidia of Mycena shengshanensis FFAAS 0424, holotype. Scale bars: 10 μm (a).