Cortinarius thindii A.Bose & K.Das, 2024

Bose, Arunima, Niskanen, Tuula, Datta, Sudeshna, Ghosh, Aniket, Vizzini, Alfredo & Das, Kanad, 2024, Two new species and a new record of Cortinarius subgenus Telamonia (Agaricales) from India, European Journal of Taxonomy 970, pp. 38-60 : 48-50

Cortinarius thindii A.Bose & K.Das sp. nov.

MycoBank MB 851198

Figs 2–3

Diagnosis

Cortinarius thindii sp. nov. is distinct from C. brunneocarpus by possessing an acutely conical and smaller pileus (40–60 mm in diam.) with dry surface, adnate to subdecurrent lamellae, stipe with a tapered base, ellipsoid to obovoid ellipsoid basidiospores and nrITS-based sequence data.

Etymology

Commemorating Dr K.S. Thind for his significant contributions to Indian mycobiota.

Type material

Holotype INDIA • Uttarakhand, Bageshwar District, Dhakuri ; 30.3261° N, 79.9388° E; 2545 m a.s.l.; 12 Aug. 2023; A. Bose & K. Das, AB23-025; on soil under Quercus semecarpifolia ; GenBank no.: PP275136 (ITS); CAL [ CAL 1968 ].

Additional material examined

INDIA • Uttarakhand, Bageshwar District, Dhakuri ; 30.0822° N, 79.9177° E; 2568 m a.s.l.; 13 Aug. 2023; A. Bose & K. Das, AB23-060; on the soil under Q. semecarpifolia ; GenBank no.: PP345589 (ITS); CAL [ CAL 1987 ].

Description

Pileus 40–60 mm diam., conical, umbo small, acute; margin tuberculate striate; surface smooth, with brownish gray (6F8–9) fibrils when young, gradually blackish brown or reddish brown (8 E 4) with orange to yellowish brown tinge centrally at maturity, turning black with KOH, surface dry, hygrophanous. Lamellae adnate to subdecurrent, distant (6–7/cm at pileus margin, lamellulae in 3 series), thin, when young brown (7 E 6), becoming blackish brown at maturity; edges entire. Stipe 61–74 mm long, 8–10 mm wide at apex, up to 12 mm at base; cylindrical, slightly curved, usually tapered towards base; surface light brown with whitish brown striations on surface, dry. Universal veil white to yellowish white, forming remnants and incomplete girdles on stipe. Basal mycelium white. Pileus context thin yellowish brown, color unchanged when bruised; stipe context fibrous, stuffed, light brown. Odor strong, raphanoid. Taste not recorded.

Basidiospores 7.0–8.9–10.2 × 4.1–4.9–5.2 μm, Q = 1.6–1.8–2.0, n = 30, ellipsoid to obovoid ellipsoid; moderately to strongly verrucose, dextrinoid. Basidia 32–40 × 12–15 μm clavate, 4-spored, with vacuolar contents. Sterile marginal elements 20–40 × 5–12 μm, cylindrical to clavate, colorless and thin-walled. Pileipellis duplex; suprapellis of compactly arranged, repent parallel hyphae, 4–8 μm wide, with yellowish intracellular pigmentations; hypoderm consisting of inflated elements 15–30 μm wide, no contents. Clamp connections present.

Remarks

The morphological features of C. thindii sp. nov., such as yellowish brown to ochre brown basidiomata, a whitish universal veil, and a strong raphanoid odor, are typical for the species of C. subg. Telamonia sect. Hinnulei .

Phylogenetically, this species is closest to C. brunneocarpus which was originally reported from Pakistan. But the Pakistani species differs from the Indian specimen by possessing a broader pileus (30–85 mm), subgloboid to obovoid basidiospores (8.5–11.5 × 6.0–8.5 µm, Q = 1.35–1.4–1.42) ( Song et al. 2019). Apart from C. brunneocarpus , C. thindii sp. nov. is phylogenetically related to C. radicosissimus Moënne-Locc (≡ C. speciosior Fr. ex Bidaud, Moënne-Locc. & Reumaux ) which was originally reported from France and morphologically it differs from the Indian material by possessing a brown to cream yellow pileus and orange to brownish lamellae (information taken from Mycodb https://www.mycodb.fr/fiche.php?genre= Cortinarius &espece =speciosior and Bidaud et al. 1997).

Figures

Fig. 2. Cortinarius thindii A.Bose & K.Das sp. nov. (holotype; A. Bose & K. Das, AB23-025, CAL). a–b. Fresh basidiomata. c. Basidia. d. Basidiospores. Scale bars: c = 10 µm; d = 2 µm.

Fig. 3. Cortinarius thindii A.Bose & K.Das sp. nov. (holotype; A. Bose & K. Das, AB23-025, CAL). a. Basidiospores. B. Basidia. c. Elements of pileipellis. d. Marginal elements. Scale bars = 10 µm.