Agaricus parasubrutilescens Callac & R.L. Zhao
Index Fungorum number: IF 570218; Facesoffungi number: FoF 01208
Pileus 85–125 mm in diam., 6–7 mm thick at disc convex, plano-convex with broad umbo, top truncate, margin deflexed; surface dry, entirely covered with fibrils, thick and dark at the centre, then broken towards margin into more minute squamules-fibrilles, not concentrically arranged, appressed, brown (6E6, 6E8), with red tinge when wet, margin exceeding. Lamellae free, crowded, intercalated with lamellulae, 6 mm broad, at first white, then light brown (7D4), brown, finally dark brown. Stipe 120–150 ×8–10 mm (apex) – 15–16 mm (base), clavate, cylindrically subbulbous, smooth and white above the annulus, with large squamules, brown or white below the annulus, not staining on touching. Annulus membranous, 10–25 mm broad, large, pendent, simple, superous, entire, lower side heavily fibrillose. Context firm, on cutting at first, white both in pileus and stipe, then turning quickly slightly orange on centre of pileus and stipe on exposure. Odour of molds, mushroomy. Macrochemical reactions: KOH and Schäffer’s reactions negative. (Fig. 2 f–h)
Basidiospores 4.2–6×3–3.5 μm [x = 4.9 ± 0.4× 3.1 ± 0.2, Q= 1.3–2, Qm= 1.58± 0.42, n=20], ellipsoid, brown, smooth, thick-walled, without germ pore. Basidia 13–20 × 5–7 μm, clavate, 4-spored. Cheilocystidia 15–28 × 10–19 μm, pyriform, hyaline, smooth. Pleurocystidia absent. Pileipellis a cutis comprising3–7.5 μm diam., brownish grey, brown, smooth, hyphae, constricted at the septa in most cases. Annulus consisting of hyphae 3–10 μm in diam., hyaline, cylindrical, some inflated-clavate, smooth, constricted at the septa. Stipitipellis consisting of hyphae 5–12.5 diam., hyaline, smooth, elongate cylindrical, curved and branched hyphae. (Fig. 3)
Habitat: solitary in rich soil of forest.
Material examined: CHINA, Yunnan Prov., Dali, Cangshan, 24 July
2014 collected by S.Y. Su ZRL2014076 (HMAS274000, holotype). THAILAND, Chiang Mai Prov., Doi Inthanon National Park, junction of Highway 1009 and road to Mae Chem, N19°31.58′ E 98°29.64′, elev. 1700 m., 27 June 2005, collected by Dennis E Desjardin, ZRL2054 (BBH19438, SFSU) and ZRL2055 (BBH19439, SFSU); same location, 5 June 2006, collected by Todd Osmundson, ZRL3020 (BBH19537, SFSU); Chiang Mai Prov., Mae Taeng, Ban Mae Sae Village, on Hwy 1095 near 50 km marker, N19°14. 599′ E98°39.456′, elev. 962 m., 26 June 2005, collected by Ruilin Zhao, ZRL2042 (BBH19427, SFSU). CHINA, Yunnan Prov., Dali, Cangshan, 31 July, 2011, collected by H.Y. Su SHY2011073115 (HMAS 274014); same location, 24 July 2014 collected by H.Y. Su, ZRL2014086 (HMAS273975), ZRL2014090 (HMAS273928) , ZRL20 1 4 11 3 (HMAS2539 1 3 ) , ZRL2 0 1 4 11 4 (HMAS273979); Yunnan Prov., Chuxiong city, Zixishan Hill, 21 June 2011, collected by R.L. Zhao, ZRL2011015 (HMAS274016); same location, 22 June 2011, collected by R.L. Zhao, ZRL2011027 (HMAS273926); Guangdong Prov., Lechang, 15 Sept. 2011, collected by X.H. Wang, ZRLWXH3151 (HMAS273959); Yunnan Prov., Nanjian County, Wuliangshan National Natural Reserve, 3 July 2012, collected by Oliver Raspe, ZRL2012025 (HMAS273968); Yunnan Prov., Cangyuan county, Nangunhe National Natural Reserve, 9 July 2012, collected by R.L. Zhao ZRL2012196 (HMAS273971); Yunnan Prov., Xianggelila, Tacheng, 5 August 2014, collected by M.L. Xu and M.Q. He, ZRL2014416 and ZRL2014419; Yunnan Prov., Weixi County, Yongchun 5 August 2014, collected by H.Y. Su, ZRL2014413 and ZRL2014448 (HMAS253914).
Fig. 1 Phylogeny of Agaricus subgenus Spissicaules generated from Bayesian analysis of ITS sequences, rooted with A. campestris. Bootstrap support (BS) values > 50 % and Bayesian posterior probability (PP) values > 80 % (or >50% in some main clades) are given at the internodes (PP/BS). BT^ means the sequence is from type specimen; a clade with thick branch is corresponding a certain section in Fig. 1