Cortinarius neodisjungendus Zhu L. Yang, Liu K. Jia & Zi R. Wang 2025, sp. nov.
Creators: name: Jia, Liu-Kun
name: Wang, Zi-Rui
name: Yang, Zhu-Liang
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Agaricales
Cortinariaceae
Cortinarius
Cortinarius neodisjungendus

description: Cortinarius neodisjungendus Zhu L. Yang, Liu K. Jia & Zi R. Wang sp. nov.
Fig. 5
Etymology.
The epithet “ neodisjungendus ” (Lat.) refers to its similarity to C. disjungendus.
Holotype.
China • Yunnan Province: Pu’er City, Jingdong Yi Autonomous County Ailao Mountain Subtropical Forest Ecosystem Research Station, Chinese Academy of Sciences, in a subtropical broad-leaved forest with trees of Quercus, 24°32.57'N, 101°1.62'E, elevation 2,532 m, 8 October 2021, Jian-Wei Liu 2505 (KUN-HKAS 145322). GenBank: ITS: PQ 772207, nrLSU: PQ 772219.
Diagnosis.
Cortinarius neodisjungendus differs from other species within sect. Disjungendi by its plano-convex pileus with an umbo, pale brown coloration, and relatively larger basidiospores (Karsten 1893; Niskanen 2014; Liimatainen et al. 2015).
Description.
Basidioma medium-sized. Pileus 3.5–4.2 cm diam, applanate to plano-convex with an umbonate center, viscid with hygrophanous streaks; pale brown to brown (6 D 3–6 D 4), dark brown (6 E 6) towards the center, white (1 A 1) to pale brown (6 B 2) towards the margin, sparsely covered with white (1 A 1) fibrillose squamules; context not observed. Lamellae emarginate, crowded (L = 52–61, l = 48–53), pale brown (6 B 4) to brown (6 D 6). Stipe 8–10 × 0.5–0.8 cm, cylindrical with a subbulbous base 1–1.5 cm wide, white (1 A 1) to pale brown (6 B 2–6 B 4), base sparsely covered with brown (6 C 5) fibrillose squamules; basal mycelium white (1 A 1).
Basidiospores [60 / 2 / 2] 11–13.5 (– 15) × (5 –) 7.5–9 μm, Q = 1.43–1.71 (– 2), av. = 12.73 ± 0.93 × 7.52 ± 0.96 μm, Qav. = 1.71 ± 0.2, broadly amygdaliform, strongly verrucose, inamyloid. Basidia 32.5–40 × 7.5–10 μm, 4 - spored, clavate. Trama of lamellae regular, composed of colorless to brownish, smooth hyphae 10–12.5 μm wide. Cystidia absent. Pileipellis duplex: epicutis weakly developed, 8.5–15 μm thick, composed of only 3–5 layers of interwoven to parallel, colorless to brownish, smooth, thin-walled, long-celled hyphae 2.5–5 µm wide; hypocutis composed of interwoven to parallel, colorless to pale brownish, cylindrical, thin-walled hyphae 12.5–15 μm wide. Clamp connections common in all parts of basidioma.
Habitat / host.
Autumn. Solitary on soil in subtropical broad-leaved forests with trees of Quercus.
Distribution.
Currently known from southwestern China.
Additional specimen examined.
China • Yunnan Province: Pu’er City, Jingdong Yi Autonomous County Ailao Mountain Subtropical Forest Ecosystem Research Station, Chinese Academy of Sciences, in a subtropical broad-leaved forest with trees of Quercus, 24°32.57'N, 101°1.62'E, elevation 2,532 m, 8 October 2021, Jian-Wei Liu 2529 (KUN-HKAS 145323).
Notes.
Cortinarius neodisjungendus is characterized by its hygrophanous, pale brown to brown pileus with a whitish margin, whitish stipe, and relatively larger basidiospores. All other species in sect. Disjungendi have a brownish pileus lacking a white margin, a brown stipe, and smaller basidiospores (range from 9–11 μm long, 6–7 μm wide) (Karsten 1893; Niskanen 2014; Liimatainen et al. 2015, 2020).
description: Published as part of Jia, Liu-Kun, Wang, Zi-Rui & Yang, Zhu-Liang, 2025, Five new species of Cortinarius (Cortinariaceae) from Yunnan, China, based on molecular and morphological evidence, pp. 145-166 in MycoKeys 116 on pages 145-166, DOI: 10.3897/mycokeys.116.146710