Cortinarius subfuscoperonatus Y. Li & M.L. Xie, 2020

Xie, Meng-Le, Wei, Tie-Zheng, Fu, Yong-Ping, Li, Dan, Qi, Liang-Liang, Xing, Peng-Jie, Cheng, Guo-Hui, Ji, Rui-Qing & Li, Yu, 2020, Three new species of Cortinarius subgenus Telamonia (Cortinariaceae, Agaricales) from China, MycoKeys 69, pp. 91-109 : 91

Cortinarius subfuscoperonatus Y. Li & M.L. Xie sp. nov. Figures 2e, f , 3c , 4c

Diagnosis.

Pileus 1.6-4.4 cm in diam. Context white, greyish-brown when moist. Basidiospores 9.5-12.1 × 7.9-9.7 μm. The ITS sequence of the holotype differs from other species in section Fuscoperonati by at least six substitutions and six indels.

Holotype.

China. Gansu Province: Zhangye City, Minle County, Gansu Qilianshan National Nature Reserve, coniferous forest ( Picea crassifolia ), 38°17'55"N, 100°45'54"E, alt. 2860 m, 9 August 2018, M.L. Xie, HMJAU44444, GenBank No. (ITS) MK552387.

Etymology.

The name refers to its affinity to Cortinarius fuscoperonatus .

Description.

Pileus 1.6-4.4 cm in diam., hemispherical when young, then low convex, weakly hygrophanous, pale greyish-brown (6C3), sometimes reddish-brown (9E5-9E6) to dark brown (6F6-6F8), surface with greyish-brown fibrillose, margin wavy with age. Lamellae emarginate, medium-spaced, reddish-brown to rusty brown (7D6-7E7), margin even when young, then slightly serrate. Stipe 2.3-7.5 cm long, 0.8-1.3 cm thick at apex, 1.5-2.5 cm thick at base, clavate, white to pale grey (E2), mycelium white at the base. Universal veil greyish-brown (6C2), rich, usually forming an annular band on the middle part and distinct belts or zones lower down. Context white (A1), greyish-brown (7F8) and marbled watery when moist, strongly hygrophanous near pileus and lamellae. Odour somewhat radish-like. Chemical reaction: pileus and context (fresh basidiomata) are dark black brown (8F3) with 10% KOH. Exsiccata brown (6E5) to dark brown (6F5).

Basidiospores 9.5-12.1 × 7.9-9.7 μm, Q = 1.10-1.45, 'X = 10.3-11.2 × 8.0-8.6 μm, 'Q = 1.24-1.33 (135 spores, 5 collections), subglobose to broadly ellipsoid, moderately to strongly verrucose, strongly dextrinoid. Basidia 4-spored, clavate, 35-58 × 10-13 μm, thin-walled, hyaline to olivaceous brown in 5% KOH. Lamellar edge fertile, with cylindrical-clavate sterile cells, 13-27 × 6-11 μm, thin-walled, hyaline to slightly olivaceous yellow in 5% KOH. Lamellar trama hyphae regular, pale olivaceous to olivaceous brown in 5% KOH, smooth. Pileipellis: epicutis hyphae cylindrical, 4-12 μm wide, slightly olivaceous brown to olivaceous brown in 5% KOH, some hyphae finely encrusted; hypocutis well developed, hyphae 24-89 × 15-29 μm, sub-cellular to sub-cylindrical, thin-walled, hyaline to slightly olivaceous brown in 5% KOH, smooth. Pileus trama hyphae almost thin-walled, hyaline in 5% KOH, smooth. Clamp connections present.

ITS sequence.

The ITS sequences of C. subfuscoperonatus are 524-525 bp long (5 collections, Table 1 ) and distinct from other members of section Fuscoperonatus . The ITS sequence of C. subfuscoperonatus (MK552387, holotype) differs from C. fuscoperonatus by six substitutions and six indels.

Ecology and distribution.

In coniferous forest ( Picea crassifolia dominated forest). Solitary or gregarious. Known from Gansu Province, China.

Additional specimens examined.

China. Gansu Province: Zhangye City, Minle County, Gansu Qilianshan National Nature Reserve, coniferous forest ( Picea crassifolia ), 38°17'55"N, 100°45'54"E, alt. 2860 m, 9 August 2018, M.L. Xie, HMJAU44445, GenBank No. (ITS) MK552388; Zhangye city, Su’nan Yugu Autonomous County, Gansu Qilianshan National Nature Reserve, coniferous forest ( Picea crassifolia dominated forest, occasionally with Juniperus ), 38°44'57"N, 99°47'56"E, alt. 3010 m, 10 August 2018, M.L. Xie, HMJAU44446, GenBank No. (ITS) MK552389, HMJAU44447, GenBank No. (ITS) MK552390; Zhangye city, Su’nan Yugu Autonomous County, Gansu Qilianshan National Nature Reserve, coniferous forest ( Picea crassifolia dominated forest, occasionally with Juniperus ), 38°33'13"N, 100°41'75"E, alt. 2700 m, 11 August 2018, M.L. Xie, HMJAU44448, GenBank No. (ITS) MK552391.

Comments.

Cortinarius subfuscoperonatus corresponds well to the characteristics of section Fuscoperonati , with weak hygrophanous pileus, an annular band on the middle stipe and distinct belts or zones lower down, large spores (> 10 µm long) and grow in coniferous forests. Cortinarius fuscoperonatus was previously placed in section Bovini M.M. Moser ( Bidaud et al. 2009; Soop 2014) and Armillati ( Brandrud et al. 1992), until Niskanen et al. (2015) placed it in section Fuscoperonati . Cortinarius subfuscoperonatus has remarkably similar morphological characteristics to C. fuscoperonatus , apart from the spores of C. fuscoperonatus being narrower (9.7-11.6 × 6.6-7.7 µm), the pileus being chocolate brown to blackish-brown and being fine fibrous to fine scaly ( Schmidt-Stohn et al. 2017). In addition, C. subfuscoperonatus formed a sister relationship with C. fuscoperonatus and was well separated according to the phylogenetic analyses. C. subfuscoperonatus could be considered as the second species in section Fuscoperonati .

Figures

Figure 2. Basidiocarps of three newly-described species. a, b Cortinarius laccariphyllus (a, b HMJAU 44449, holotype); c, d Cortinarius neotorvus (c HMJAU 44441, holotype; d HMJAU 44439); e, f Cortinarius subfuscoperonatus (e HMJAU 44444, holotype; f HMJAU 44445). Scale bars: 2 cm (a, b, d-f). Photographs by Meng-Le Xie.

Figure 3. Basidiospores of three newly-described species. a Cortinarius laccariphyllus (HMJAU 44449, holotype); b Cortinarius neotorvus (HMJAU 44441, holotype); c Cortinarius subfuscoperonatus (HMJAU 44444, holotype). Photographs by Meng-Le Xie.

Figure 4. Margin cells of three newly-described species. a Cortinarius laccariphyllus (HMJAU 44449, holotype); b Cortinarius neotorvus (HMJAU 44441, holotype); c Cortinarius subfuscoperonatus (HMJAU 44444, holotype). Photographs by Meng-Le Xie.