Mallocybe luteoaurantiaca Sattar, Kiran & Khalid sp. nov. (Figs. 2, 3 & 4)

MycoBank:—MB859265

Etymology:—The specific epithet “ luteoaurantiaca ” (Latin) refers to the yellow-orange color of the basidiomata.

Diagnosis:— Mallocybe luteoaurantiaca, is distinct from its most closely related species (M. fuscomarginata) in having a hemispherical to parabolic, smooth, and bright brown to yellow-orange pileus, pale yellow to yellow-orange and adnate to sinuate lamellae, longer (30–50 mm) and bright brown to yellow-orange stipe, absence of cortina, and slender and narrowly utriform to utriform cheilocystidia (4–7 µm)

Holotype:— PAKISTAN. Khyber Pakhtunkhwa, Upper Dir District, Kumrat Valley, Bargai, 35.53708° N, 72.21931° E, 2359 m a.s.l. on forest floor, 22 August 2017, Munazza Kiran & Abdul Nasir Khalid, BAR3 (LAH35911!; ITS: PV652465; LSU: PV652467).

Description:—Basidiomata medium-sized. Pileus 30–50 mm diam., hemispherical to spherical, broadly parabolic when young, becoming wider towards maturity, sometimes cracked or rimose upon maturity; margin initially decurved, becoming straight upon maturity; surface smooth, bright brown (7.5YR 5/8) at center, becoming lighter yellow-orange (2.5Y 8/4) in patches towards margin. Lamellae adnate to sinuate, regular, ventricose to broadly ventricose, subdistant to close, with entire edges; pale yellow (5Y 8/4) when young, becoming concolorous with the pileus with age. Lamellulae wavy, numerous, variable in length, alternating with lamellae. Stipe 30–50 mm long, central, solid, narrower at the apex, gradually becoming broader towards the base, slightly fibrillose, concolorous with the pileus. Annulus absent. Context of pileus and stipe pale yellow (2.5Y 8/4). Taste not checked. Odor unpleasant. No color reaction of the pileus to alkali was detected.

Basidiospores [40/2/2], (10.0–)10.95–12.04(–12.87) × (6.0–)6.78–7.13(–7.89) µm, (avL × avW=11.45 × 6.96 µm), Q=1.7, oblong to ellipsoid, guttulate, apiculate, smooth, thin-walled, reddish brown in KOH, inamyloid. Basidia 35.2–52.5 × 8.8–11.4 µm, clavate to sub-clavate, two to four sterigmate, thin-walled, hyaline to light green (5G 9/2) necropigment, hyaline in 5% KOH. Pleurocystidia absent. Cheilocystidia 16.6–20 × 4–7 µm, narrowly utriform to utriform, rare, hyaline in 5% KOH. Pileipellis a cutis, hyphae 7.2–9.8 µm, cylindrical, intertwined, broader toward pileal apex, narrower in the mat, hyaline in 5% KOH. Stipitipellis a cutis, with hyphae 5.4–9.9 µm in diam, branched, parallel, septate, and hyaline in KOH. Clamp connections present in all tissues.

Habit and Habitat:—Found gregariously on soil in forests of mixed deciduous trees in Kumrat Valley, Upper Dir District, Khyber Pakhtunkhwa, Pakistan.

Additional material examined: PAKISTAN. Khyber Pakhtunkhwa, Upper Dir District, Kumrat Valley, Bargai, 35.53708° N, 72.21931° E, 2359 m a.s.l. on forest floor, 22 August 2022, Munazza Kiran & Abdul Nasir Khalid (LAH38734!; ITS: PV654055; LSU: PV654061).