Cortinarius dhakuricus A. Bose & K. Das 2024, sp. nov.
Creators: name: Bose, Arunima
name: Niskanen, Tuula
name: Datta, Sudeshna
name: Ghosh, Aniket
name: Vizzini, Alfredo
name: Das, Kanad
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Agaricales
Cortinariaceae
Cortinarius
Cortinarius dhakuricus

description: Cortinarius dhakuricus A.Bose & K.Das sp. nov.
MycoBank MB 851486
Figs 4–5
Diagnosis
Cortinarius dhakuricus sp. nov. is separated from all the known species from India by possessing very prominent silvery to yellowish white squamules on pileus surface and lamellae that are broadly attached with rare bifurcations and nrITS-based sequence data.
Etymology
Referring to Dhakuri (of the state of Uttarakhand, India), the type locality.
Type material
Holotype INDIA • Uttarakhand, Bageshwar District, Dhakuri; 2870 m a.s.l.; 30.0711° N, 79.9204° E; 13 Aug. 2023; A. Bose & K. Das, AB23-033; on the soil under Quercus semecarpifolia; GenBank no.: PP316707 (ITS); CAL [CAL 1970].
Additional material examined
INDIA • Uttarakhand, Bageshwar District, Dhakuri; 2901 m a.s.l.; 30.0711° N, 79.9204° E; 14 Aug. 2023; A. Bose & K. Das, AB23-055; on the soil under Q. semecarpifolia; GenBank no.: PP345590 (ITS); CAL [CAL 1986].
Description
Pileus 14–20 mm diam., acutely conical when young, becoming conico-umbonate or obtusely umbonate, with an acute umbo; margin entire; surface grayish brown, covered with very prominent silvery to yellowish white squamules, umbo reddish brown, turning maroon brown with KOH; dry, hygrophanous. Lamellae broadly attached, sinuate, rarely forked; subdistant (8–10/cm at pileus margin, lamellulae in 5 series), rather thick; reddish brown (9D4); edges dentate. Stipe 38–50 mm long, 5–7 mm thick at apex, up to 10 mm thick at base, cylindrical to somewhat enlarged below, slightly tapered towards very base, with longitudinal striate; surface yellowish brown, turning light yellow with KOH, dry. Universal veil forming a yellowish white membranous annular zone on upper part of stipe and some incomplete and complete girdles lower down. Basal mycelium yellow-white. Pileus context brown, color unchanging when bruised; stipe context stuffed, consistency brittle. Odor strongly raphanoid. Taste not recorded.
Basidiospores 8.0–8.7–10.0 × 4.1–5.9–6.0 μm, Q = 1.5–1.71–2.12, ellipsoid to obovoid-ellipsoid, (moderately) to strongly verrucose dextrinoid. Basidia 30–37 × 10–20 μm, 4-spored, clavate. Sterile marginal elements 20–30 × 6–10 μm, cylindrical to clavate, colorless and thin-walled, clamped at the base. Pileipellis composed of compactly arranged, cylindrical, repent parallel hyphae giving rise to frequent squamules; each squamule composed of clusters of isodiametric pseudoparenchymatous elements to bulbous (inflated) erect hyphae in clusters that form the squamule tip at regular to irregular intervals; terminal elements of squamules 29–51 × 15–35 μm, subcylindrical to ventricose with rounded or rarely mucronate apex.
Remarks
Based on available sequences in the public database it appears that C. dhakuricus sp. nov. has no known sister taxa in the section. However, because of its conic-umbonate pileus with squamulose surface it partly resembles another Himalayan species C. dombangensis K.Das, D.Chakr., A.Ghosh & Vizzini (originally reported from India), but the latter is segregated from the former by possessing a silky stipe which is encircled with complete to incomplete irregular whitish bands of velar remnants in multiple rows, with a yellowish white membranous annular zone, and occurs under Abies densa Griff.; C. dombangensis is also segregated based on its nrITS-based sequence data (Das et al. 2022).
description: Published as part of 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, pp. 38-60 in European Journal of Taxonomy 970 on pages 50-53, DOI: 10.5852/ejt.2024.970.2747, http://zenodo.org/record/14239023