Lepiota sindhudeltana sp. nov. (Agaricaceae; Basidiomycota) from Punjab, Pakistan Author Haqnawaz, Muhammad Author Niazi, Abdul Rehman Author Usman, Muhammad Author Khalid, Abdul Nasir text Phytotaxa 2022 2022-06-16 550 3 253 262 journal article 77013 10.11646/phytotaxa.550.3.5 9ad9458b-24b5-4c40-a1aa-bdb3b73c4180 1179-3163 6651032 Lepiota sindhudeltana Haqnawaz, Niazi, Usman & Khalid sp. nov . ( Figs. 1 , 2 ). MycoBank MB843317 Etymology:—‘ sindhudeltana ’ (Latin) refers to the locality of the taxon i.e ., the delta of the River Sindh (Indus River). Diagnosis:—It differs from Lepiota angusticystidiata by having dull orange to light gray squamules, thin and dull orange pileal context, absence of velar elements on pileus, pale yellow lamellae, stipe base slightly oblong to rounded, fibrillose annulus, broadly ellipsoid to oblong, basidiospores neither dextrinoid nor amyloid, short pileal elements, and narrowly clavate, mucronate stipitipellis elements. Holotype :— PAKISTAN . Punjab , Muzaffargarh district , Indus Riverbed near Bet Essan Wala , ( 30°14’44”N , 70°51’04”E , 134 m a.s.l. ) on soil, rich in organic matter, 29 August 2020 , Muhammad Haqnawaz , EF 01 (LAH37025). GenBank OM987446 (ITS) and OM987442 (LSU). FIGURE 1. A–E. Fruitbodies of Lepiota sindhudeltana sp nov ( A . Holotype LAH37025). Scale bars: A–D = 10 cm. Photos by: Muhammad Haqnawaz. FIGURE 2 . A—F . Microscopical structures of L. sindhudeltana (Holotype. LAH37025) A . Basidia, B . Basidiospores, C . Cheilocystidia, D . Stiptipellis, E . Short clavate pileal elements F . Erect long Pileal elements, G . Terminal elements of stipe, Scale bars: A–C = 5 µm, D–G = 10 µm. All elements in Congo Red. Photos by: Muhammad Haqnawaz. FIGURE 3 . Molecular phylogenetic placement of Lepiota sindhudeltana based on Maximum Likelihood (ML) method of ITS sequences. The new species is in bold. Description:— Fruitbodies small, gregarious. Pileus 6–27 mm diam, campanulate to parabolic when young, becoming convex to umbonate at maturity, margin decurved becoming straight at maturity, dull orange (5 YR6/3) when young with dull orange (7.5 YR 7/3) squamules at center becoming light yellow (10 YR 8/2) towards margin, then with maturity dull brown (7.5 YR 6/3); squamules at center becoming light gray (10 YR 8/1) toward margin on light yellow (10 YR 8/2) background; context soft, thin ca. 1 mm and dull orange (5 YR6/3). Lamellae free, moderately close with 2 tiers of lamellulae, pale yellow (2.5 YR 8/3); margin fimbriate, concolorous with faces. Stipe 11–26 × 2–3 mm , central, cylindrical, fibrillose, pale yellow (2.5 YR 8/3), with light orange (5 YR 8/3) squamules over surface, hollow, base of stipe slightly oblong to rounded, Volva absent. Taste , odor and spore print not recorded. FIGURE 4. Molecular phylogenetic placement of Lepiota sindhudeltana based on Maximum Likelihood (ML) method of ITS-LSU combined sequences. The new species is in bold. Basidiospores [100/4/4] (5.8–) 6.1–7.5 (–8.0) × (4.3–) 4.4–5.6 (–5.8) µm, Q = 1.16–1.65, Qav = 1.29, mainly broadly ellipsoid, a few oblong, yellowish in 5 % KOH, neither amyloid or dextrinoid, thick-walled, smooth, guttulate. Basidia (22.8–) 23.9–33.4 (–33.6) × (6.6–) 7.0–8.8 (–9.5) µm, clavate, hyaline in 5 % KOH, thin-walled, smooth, with 1–4 sterigmata; clamped at base. Cheilocystidia (21.9–) 22.0–30.6 (–31.8) × (7.2–) 7.3–9.6(–10.0) µm, fusiform to narrowly clavate, hyaline in 5 % KOH, thin-walled, clamped at base. Pleurocystidia absent. Pileipellis an irregular trichoderm composed of erect, narrowly clavate elements, 35–84 × 12–22.7 µm, and broadly clavate elements 21.9–41 × 5.1–9.5 µm with light brown intracellular pigments hyaline in 5 % KOH, thin-walled, septate, branched, clamp connections present. Stipitipellis a trichoderm composed of hyphae 5.3–11.8 µm diam, hyaline in 5 % KOH, thinwalled, septate, branched, clamp connections present. Terminal elements narrowly clavate, mucronate, 38.2–90 × 8.3–20.7 µm, hyaline in 5 % KOH, clamp connections present. Habit, habitat and distribution:—Terrestrial, solitary, present on sandy soil under Saccharum bengalense Retz. , collected during monsoon season. Additional specimens examined:— PAKISTAN . Punjab , Muzaffargarh district , Kot Addu , Bed of Indus River , Bet Essan Wala , ( 30°14’44”N , 70°51’04”E , 134 m a.s.l. ) 29 August 2020 , Muhammad Haqnawaz EF 07 , (LAH37024), GenBank OM987445 (ITS); 29 August 2020 , Muhammad Haqnawaz EF 09 (LAH37026) GenBank OM987447 (ITS) and OM987441 (LSU) ; Punjab , Lahore district , bank of River Ravi , Jhok Reserve Forest , ( 31°26’02”N , 74°08’22”E , 202 m a.s.l. ) 23 August 2020 , Muhammad Haqnawaz & Abdul Nasir Khalid MN 03 (LAH37027), GenBank OM987448 (ITS) .