Agaricus sect. Xanthodermatei (Agaricales) of West Bengal, India Author Tarafder, Entaj 0000-0002-3680-3433 Department of Plant Pathology, Agriculture College, Guizhou University, Guiyang, Guizhou Province, 550025, People’s Republic of China. & Molecular and Applied Mycology and Plant Pathology Laboratory, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, West Bengal 700019, India. entajtarafder@gmail.com Author Dutta, Arun Kumar 0000-0001-5234-3441 Department of Botany, Gauhati University, Gopinath Bordoloi Nagar, Jalukbari, Guwahati - 781014, Assam, India. arun.botany@gmail.com Author Karunarathna, Samantha C. 0000-0001-7080-0781 Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, People’s Republic of China. samanthakarunarathna@gmail.com Author He, Mao-Qiang 0000-0002-9300-7484 State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People’s Republic of China. hemaoqiangleo@gmail.com Author Tian, Fenghua 0000-0002-6962-9531 Department of Plant Pathology, Agriculture College, Guizhou University, Guiyang, Guizhou Province, 550025, People’s Republic of China. fhtian@gzu.edu.cn Author Acharya, Krishnendu 0000-0003-1193-1823 Molecular and Applied Mycology and Plant Pathology Laboratory, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, West Bengal 700019, India. krish_paper@yahoo.com text Phytotaxa 2023 2023-12-21 630 4 245 265 https://phytotaxa.mapress.com/pt/article/download/phytotaxa.630.4.1/51380 journal article 282878 10.11646/phytotaxa.630.4.1 814688d9-acb1-49e2-911d-e3484c0e9bdd 1179-3163 10417658 Agaricus punjabensis Qasim, A. Ashraf & Khalid, Phytotaxa 252(1): 8 (2016) ( Figures 2f , 5 ) Index Fungorum Number: 814981 Pileus 42–75 mm in diameter, hemispherical to dome shaped when young, later slightly umbonate, then finally plano-convex with a depression around the umbo at maturity; surface dry, uniformly covered with innates, brownish grey (7F2) to dark brown (7F4) appressed fibrils on a white background, becoming radially fibrillose, splitting radially upon expansion; margin entire, slightly uplifted when mature, appendiculate with partial veilar remnants; context 7 mm thick at centre, white (1A1), fleshy, colour turns light yellow (1A4) on cutting. Lamellae free, 4–6 mm broad, very crowded; with 4–5 series of intercalated lamellulae, pinkish when young, becoming dark brown (6F8) on maturity; regular, edge even, concolorous. Stipe 40–80 × 5–12 mm , central, curved at the middle, surface smooth, white (1A1) to cream above the annulus, dark brown (6F5) below the annulus, dark greyish brown (6E3) at the base, light brown (6D5-6) near the annulus, colour turns light yellow (1A5) on cutting, marginate base (up to 16 mm ) without rhizomorphs. Annulus superous, double, membranous, upper surface smooth, lower surface with scales arranged in a cogwheel, thick, 37 mm diam., white (1A1). Odour indistinct. Basidiospores [35,1,1] (5.0–)5.9–6.8(–8.5) × (3.2–)4.1–4.7(–5.6) μm, X m = 6.4 ± 0.9 × 4.4 ± 0.6 μm, Q = 1.3– 1.6, Q m = 1.5 ± 0.07, ellipsoid, smooth, dark brown with KOH, thick-walled. Basidia 15–18 × 5–7 μm, clavate, hyaline, occasionally gluttulate, thin-walled, smooth, 4-spored, sterigmata 1.5–3 µm long. Basidioles 12–15 × 6–7 μm, clavate, hyaline, thin-walled, smooth. Cheilocystidia 11–16 × 6–8 μm, sub-clavate to sphaeropedunculate, hyaline, thin-walled, smooth. Pleurocystidia absent. Pileipellis a cutis, hyphae 7–10 μm broad, branched, short inflated cells with brown diffused pigments, thin-walled, smooth. Stipitipellis hyphae 5–7.5 μm broad, light brown with KOH, thin-walled. Annulus composed of long cylindrical hyphae, 6–8.5 μm broad, hyaline with KOH, not constricted at the septa, smooth, thin-walled. FIGURE 5. Agaricus punjabensis . (a) Basidiospores (b) Basidia (c) Basidioles (d) Cheilocystidia (e) Pileipellis hyphae. Scale bars: a–d = 5 μm, e = 10 μm. Drawing by: E. Tarafder Macrochemical reactions:—KOH reaction positive, pileus surface and context turning yellow (2A6), stipe surface and context changing to yellow (2A6); Schäffer reaction on pileus surface negative. Habit and habitat:—solitary to gregarious, terrestrial on humus soil under a dicotyledonous tree. Specimen examined:— INDIA : West Bengal , South 24-parganas District, Mathurapur, Halder Para, 22°7’14.85”N , 88°23’29.14”E , alt. 7.0 m asl., 04 August 2019 , E. Tarafder, CUH AM758. Remarks:— Agaricus punjabensis was described for the first time in Pakistan ( Chen et al . 2016 ). The occurrence of this species in India represents its first record outside of Pakistan . The Indian collection matches quite nicely with the original protologue but differs in having larger basidiospores (5–8.5 × 3.2–5.6 μm vs. 3.5–5 × 2.5–3.5 μm). Agaricus punjabensis shares morphological features with A. endoxanthus Berk. & Broome , A. volvatulus Heinem. & Gooss. -Font., A. moelleri Wasser , and A. microvolvatulus Heinem. However , A. endoxanthus Berk. & Broome has a stipe the surface of which is unchanging on bruising and much larger globose to clavate cheilocystidia (14–32 × 10–17 μm vs. 11–16 × 6–8 μm), pyriform, turbinate or subspherical ( Parra et al . 2013 ). Agaricus volvatulus Heinem. & Gooss. -Font., has much smaller basidiospores (4.7–5.7 × 3.2–3.7 μm) and an absence to rare presence of cheilocystidia ( Heinemann 1956 ). Agaricus moelleri Wasser differs by its entirely white stipe and much larger cheilocystidia (10–28 × 7.0–20 μm; Parra 2013 ). Agaricus microvolvatulus Heinem. differs by its smaller basidiospores (3.8–4.8 × 2.8–3.3 μm) and much broader cheilocystidia (7.0–12.5 μm broad; Heinemann 1971 ).