Leucoagaricus gujratensis A. Rehman, Usman, Afshan & Khalid, 2023

Rehman, Amatu, Usman, Muhammad, Afshan, Najam Ul Sehar & Khalid, Abdul Nasir, 2023, Leucoagaricus gujratensis sp. nov. (Agaricaceae, Agaricales) from Pakistan, Phytotaxa 589 (1), pp. 39-50 : 43-47

Leucoagaricus gujratensis A. Rehman, Usman, Afshan & Khalid , sp. nov.

( Figures 1–2 )

MycoBank: MB845724

Etymology: The specific epithet “ gujratensis ” (Latin) refers to the type locality “Gujrat District”.

Diagnosis: This species is characterized by milky white pileus surface with brown furfuraceous squamules, lacrymoid to amygdaliform basidiospores (5.4–8.6 × 3.9–5.5 μm) with abundant clavate to slightly fusiform, fabiform cheilocystidia, pileipellis with periclinal hyphae to irregularly ascending, cylindrical and septate hyphae wide as cutis with light brown terminal end.

Holotype: PAKISTAN. Punjab Province, Gujrat District (32°52’4.71”N 74° 7’35.85”E), 311 m a.s.l., on soil with leaf litter under Dalbergia sissoo Roxb. , August 18, 2021, AG02, Amatu Rehman & Amanat Hussain (LAH37457). GenBank: OP526420 (ITS), OP885328 (LSU).

Pileus 52–92 mm in diam., campanulate, expanding to convex to plano-convex or umbonate with small umbo with light brown (7.5YR 6/6) to dark brown (5YR 2/4) and incurved margins, smooth, shiny with brown (5YR 3/4) to light brown (7.5YR 5/4) glabrous around umbo on milky white (7.5Y 9/1) pileus surface that shows radial streaks towards margin. Lamellae milky white, close to distant, 1–3 series of lamellulae, with entire edges. Stipe 3.2–5.0 × 2.8–3.9 mm, pinkish white (10YR 7/3) to slightly brown (5YR 5/6), central, hollow, fibrillose, narrower towards the pileus.Annulus milky white (7.5Y 9/1), prominent, membranous, ascending. Context milky white (7.5Y 9/1). No color change on handling. Odor and taste not tested.

Basidiospores [100/6/4] (5.4–)5.5–8.5(–8.6) × (3.9–)4.4–5.4(–5.5) μm, Q = (1.2–)1.3–1.4(–1.5), Qav = 1.35, amygdaliform in side view, narrowly ovoid in frontal view, hyaline in KOH, with refractive guttules, slightly thick walled (less than 3–4 μm), smooth, without a germ pore, dextrinoid. Basidia 12.9–25.4 × 7.6–11.8 μm, clavate, hyaline in KOH, bearing 1–4 sterigmata up to 3–5 μm long. Pleurocystidia absent. Cheilocystidia 7.9–27.2 × 5.7–12.8 μm, abundant, tightly packed, forming a sterile edge, clavate to slightly fusiform, fabiform, hyaline in 5% KOH, without crystal content. Pileipellis as cutis made up of periclinal hyphae to irregularly ascending, cylindrical to sub-cylindrical, slightly overlapping, septate hyphae 5.2–9.2 μm wide, light brown colored terminal ends, thin-walled to slightly thickwalled. Stipitipellis as cutis with repent, cylindrical, septate hyphae 2.4–5.8 μm wide, hyaline, thin walled. Annulus hyphae 4.2–8.2 μm wide, cylindrical to elongate, hyaline elements in 5% KOH. Clamp connections absent in all tissues.

Habit and Habitat: Saprotrophic and solitary on sandy soil, rich in leaf litter under Dalbergia sissoo trees. Fruiting during Monsoon.

Additional specimens examined: PAKISTAN. PUNJAB, Gujrat District (32°52’16.30”N 74° 7’30.32”E), 315 m a.s.l., August 18, 2021, AG 22, Amatu Rehman & Amanat Hussain (LAH37458), GenBank: OP526421 (ITS), OP885329 (LSU), (32°86’9N 74°13’1E) 313 m a.s.l., July 26, 2022, AR 41, Amatu Rehman & Amanat Hussain (LAH37607), (32°51’58.55”N 74° 7’27.47”E) 314 m a.s.l., August 07, 2022, AR 42, Amatu Rehman & Amanat Hussain ( LAH 37608).

Figures

FIGURE 1. A–C. Fresh fruiting bodies of Leucoagaricus gujratensis (holotype, LAH37457). Photos by Amatu Rehman.

FIGURE 2. A-F. Anatomical characters of Leucoagaricus gujratensis (LAH37457, holotype), A. basidiospores, B. basidia, C. Cheilocystidia, D. Stipitipellis, E. Pileipellis, F. Hyphae of annulus. Drawings by Amatu Rehman.