Clitopilus cretoalbus A.Izhar, Zaman, M.Asif, H.Bashir, Niazi & Khalid, 2023

Izhar, Aiman, Khan, Zaman, Asif, Muhammad, Bashir, Hira, Rani, Afifa Kainat, Niazi, Abdul Rehman & Khalid, Abdul Nasir, 2023, Clitopilus cretoalbus sp. nov. (Entolomataceae, Agaricales), a new species from Pakistan, European Journal of Taxonomy 861, pp. 168-184 : 174-179

Clitopilus cretoalbus A.Izhar, Zaman, M.Asif, H.Bashir, Niazi & Khalid sp. nov

Mycobank: MB843564

Figs 3–4

Diagnosis

Clitopilus cretoalbus sp. nov. is close to C. scyphoides but the latter differs by its hygrophanous pileus with smaller diameter (3–6 mm), short stipe (4–9 mm), small colourless basidiospores (5–7 × 3.5–4.5 µm), absence of cystidia and pale yellow pileipellis.

Etymology

The specific epithet ʻ cretoalbus ʼ refers to chalk white colour of basidiocarps.

Type material

Holotype PAKISTAN – Punjab Province • Sheikhupura; 31°42′40″ N, 73°59′16″ E; 236 m a.s.l.; 3 Aug. 2017; A. Izhar Skp 102; GenBank nos: ON117610 (nrITS), ON229505 (nrLSU); LAH[35709] .

Additional material examined

PAKISTAN – Punjab Province • Sheikhupura; 31°42′40″ N, 73°59′16″ E; 236 m a.s.l.; 20 Jul. 2018; A. Izhar Skp 106; GenBank no.: ON229117 (nrITS); LAH[37112] • same data as for preceding; 12 Aug. 2021; A. Izhar Skp 107; GenBank no.: ON229118 (nrITS); LAH[37113] • Lahore, Jhok Reserve Forest ; 31°25ʹ36.01ʺ N, 74°7ʹ11.13ʺ E; 217 m a.s.l.; 23 Aug. 2020; A.N. Khalid MN16; GenBank nos: OM935685 (nrITS), OM934826 (nrLSU); LAH[37017] • Bahawalpur, Lal Suhanra National Park , under Bombax ceiba L.; 31°26′28″ N, 74°8′7″ E; 125–140 m a.s.l.; 5 Sep. 2020; M. Asif AG130; GenBank no.: ON241754 (nrITS); LAH[37111] • Khushab, Noorpur Thal , Peelowains ; 32°20′ N, 72°20′ E; 185 m a.s.l.; 8 Aug. 2021; Z. Khan & J. Khan PW18; GenBank no.: OM935686 (nrITS); LAH[37016] . – Khyber Pakhtunkhwa Province • Swat, Tehsil Kabal , Village Deolai ; 34°34′ N, 72°08′ E; 1000 m a.s.l.; 25 Jul. 2021; H. Bashir GHSS02; GenBank no.: ON326583 (nrITS); LAH[37126] .

Description

Basidiomata clitocyboid, infundibuliform, or omphaloid, usually very small in size. Pileus 25–30 mm, concave, infundibuliform or umbilicate, context very fragile, white (2.5YR9/2), later chalk white, pale yellow at the disc (5Y 8/3), small brown patches develop when touched or dried, umbo never found, surface smooth to finely fibrillose under the lens, margins inrolled, becoming relatively straight towards maturity, cracks or furcations develop at pyramidal portions. Lamellae adnate to deeply decurrent, very thin, membranous, somewhat distant to close, sometimes bifurcated, white (2.5YR9/2) concolorous to pileus, up to 1.8 mm in height, edges entire, lamellulae abundant, present in 1–3 tiers. Stipe 10–25 × 1–4 mm, almost central, slightly eccentric in a few specimens, sub-cylindrical, concolorous to pileus, surface smooth or minutely pubescent, white mycelium at the base. Odor farinaceous.

Basidiospores [100/5/5] (4.5–)6.4–7.5(‒8.5) × (3.6‒)3.9–4.6(‒5.5) μm, avl × avw = 6.7 × 4.4 μm, Q = 1.2‒1.54, avQ = 1.5, oblong, broadly ellipsoid or amygdaliform, hyaline to pale in 5% KOH, thin-walled, smooth-walled, frequent lipidic guttules, apiculus prominent, mostly isolated, few in tetrads. Basidia 13‒25 × 6.3‒8 μm, avl × avw = 18.7 × 7.2 μm, clavate, hyaline in 5% KOH, 4-spored, rarely 2-spored, sterigmata up to 3–3.4 µm in length, no clamp connections at base. Cheilocystidia 17‒30 × 5.5‒8.8 μm, avl × avw = 23 × 7 μm, polymorphic, subcylindrical, lageniform, some filiform, septate, few with apical or lateral outgrowths, resembling end cells of pileipellis, hyaline to pale in 5% KOH, often present in clusters. Pleurocystidia not found. Sub-hymenium irregular in texture, composed of 2–3 layers of ellipsoid hyphal elements, 3–13 × 4–8 μm. Pileipellis consists of a cutis of hyaline to pale cylindrical thin-walled hyphae 4–8 μm wide, avw = 6.2 μm, few pigmented brownish, hyphae parallel, often interwoven, many isolated and clustered ascendingly, terminal elements 5–8 μm wide. Pileal trama consists of subregular, hyaline, thin-walled, relatively inflated hyphae 8–14 μm wide, few oleiferous hyphae present. Stipitipellis a cutis composed of hyaline, loosely arranged or interwoven hyphae 4–5.5 μm wide, thin-walled, many clustered ascendingly.

Habitat

Scattered or in small groups on nutrient-rich loamy soil and gregarious in grassy plots.

Known distribution

Currently only known from Pakistan.

Figures

Fig. 3. A–F. Morphology of Clitopilus cretoalbus A.Izhar, Zaman, M.Asif, H.Bashir, Niazi & Khalid sp. nov.A–B. Basidiomata of Skp102 (holotype, LAH35709). C–D. Basidiomata of Skp106 (LAH37112) in natural habitat. E–F. Basidiomata of MN16 (LAH37017). Photographs by Aiman Izhar, Muhammad Asif & Zaman Khan. Scale bars = 10 mm.

Fig. 4. A–F. Microscopic characters of Clitopilus cretoalbus A.Izhar, Zaman, M.Asif, H.Bashir, Niazi & Khalid sp. nov. (Skp102). A. Basidia. B. Basidiospores. C. Cheilocystidia. D. Pileipellis. E. Stipitipellis. Drawings by Aiman Izhar. Scale bars = 10 μm.