Chlorophyllum demangei (Pat.) Z.W. Ge & Zhu L. Yang
Index Fungorum number: IF 823863; Facesoffungi number: FoF 07067
Pileus 50–90mm, subglobosewhen young, expanding to parabolic, convex-hemispherical with umbo, applanate to plano-concave, with straight to the deflexed margin; surface smooth when young, brownish-grey (5D2), later breaking up into scales and leaving light-brown to brown (5D4, 6D7–8) glabrous calotte at the center, with concolorous with tufted patches around umbo and irregular patches scattered toward the margin, on white to pale-yellow (5A3) background, turning orange-white (5A2) with time; margin with strongly sulcate marginal zone, striate, up to 15 mm wide, with exceeding lamellae when mature. Lamellae free, slightly or distinctly ventricose, up to 5 mm wide, white to yellowish-white (4A2), crowded, lamella-edge eroded. Stipe 10–90 × 6–7 mm, cylindrical, or slightly wider at base; surface covered with white fibrils, turning orange-white (5A2) when touched. Annulus superonate, attached at the upper side of the stipe, moveable when mature, with surface concolorous to patches on the pileus. The context in pileus white, in stipe white and hollow, turning orange-white (5A2) in both stipe and pileus context. Taste peanut-like. Smell mild. Spore print white.
Basidiospores [100,4,4] 6.5–8.5 × 4.2–6.5 µm, avl × avw = 7.5 × 5.5 µm, Q = 1.3–1.67, Qav = 1.4–1.55, in side-view ellipsoid to oblong-amygdaliform, in frontal view ellipsoid, oblong, without germ pore, slightly thick-walled, hyaline, dextrinoid, congophilous, cyanophilous, metachromatic in Cresyl Blue. Basidia 18–28 × 7.0–11.5 µm, clavate, hyaline and thin-walled, 2-spored and 4-spored, occasionally 1-spored. Lamella edge sterile, with abundant cheilocystidia. Cheilocystidia 24–55 × 6–9.5 µm, narrowly clavate, slightly narrowly lageniform, cylindrical, colorless, and slightly thick-walled. Pleurocystidia absent.
Habitat and distribution: Solitary or in large groups, saprotrophic, on decaying wood and leaves on rich humus soil; in deciduous rainforest, gardens, and grasslands.
Material examined: THAILAND, Chiang Mai Province, Mae Taeng District, Pha Deng Village: 19_07013.700 N; 98_43052.900 E, alt., 905 m, 6 July 2007, P. Sysouphanthong, PNG05 (MFLU 09-0005); ibidem, 12 July 2007, P. Sysouphanthong, PNG050 (MFLU 09-0051); ibidem, 25 July 2007, E. C. Vellinga, ecv3557; ibidem, 15 July 2007, E. C. Vellinga, ecv3622; Chiang Rai, Muang District, Pong Phra Bath Village, 21 July 2012, P. Sysouphanthong, 2012-6 (MFLU 12-1769).
Notes: the Thai collections of Chlorophyllum demangei can be recognized by brownish-grey to yellowish-brown irregular patches on white pileus with sulcate or striate margin in most collections, white and free lamellae with a white spore print, a simple annulus, oblong-ovoid to oblong amygdaliform, and hyaline basidiospores without a germ pore, clavate, 4-spored basidia, narrowly clavate to cylindrical cheilocystidia, trichodermal pi-leus covering made up of cylindrical to narrowly clavate elements, and absence of clamp connection. It closely resembles C. hortense, microscopically because of the basidiospores without a germ pore and the cylindrical cheilocystidia, but it differs in the 4-spored basidia. Thus far, it seems to be much more restricted in its distribution than C. hortense, as it is only known from China, northern Thailand, and Vietnam (Ge et al. 2018, Patouillard et al. 1907). This is the first record of the species from Thailand.
Fig 1. Maximum Likelihood tree of Chlorophyllum based on analysis of nrITS-LSU-rpb2 sequence data. Bootstrap values (ML/B) are given above the branches. Bootstrap values for maximum likelihood equal to or greater than >60 and Bayesian posterior probabilities >0.95 are placed above the branches. Abbreviations are as follows: A. = Agaricus, C = Chlorophyllum, and Cl = Clarkeinda. Clarkeinda trachodes and Agaricus campestris are used as outgroup. New sequences are in bold type.