Agaricales » Entolomataceae » Clitopilus

Clitopilus yunnanensis

Clitopilus yunnanensis S.P. Jian & Zhu L. Yang

Basidiomata paxilloid to clitocyboid, medium-sized. Pileus 30–50 mm wide, plano-convex to convex, often slightly depressed at center; surface grayish brown (1C1–2) to yellowish brown (1C3–5), paler with age, viscid when wet, slightly squamulose at first, soon smooth; margin incurved, then slightly expanded over time; context 4–8 mm thick, white (2A1). Lamellae decurrent, whitish (1A1–B1), then pinkish (4A4–5), crowded, up to 5 mm in height, edges entire and concolorous, lamellulae numerous. Stipe 20–55 × 4–14 mm, central and equal, subcylindrical to cylindrical; surface whitish gray (4B1) to grayish yellow (4B2–3); basal part usually with white (1A1) mycelium when young, but reduced over time. Odor strongly farinaceous. Basidiospores (6–)7–11(–12) × 5–8 μm, Lm × Wm = 8.88 (± 0.88) × 6.17 (± 0.54) μm, Q = (0.93–)1.00–1.85 (–1.87) (Qavg = 1.45 ± 0.19) [91/4/4], hyaline, slightly thick-walled (<0.5 μm), subovoid to subfusiform or fusiform, sometimes amygdaliform to limoniform in profile and face view, strongly angled in polar view with 5–7(8) obvious longitudinal ridges. Basidia 17–37 × 7–13 μm, clavate, hyaline, 4-spored, rarely 2-spored; sterigmata 3–4 μm long. Lamellar trama regular, composed of 3–12 μm wide, hyaline hyphae; oleiferous hyphae rare; subhymenium consisting of filamentous hyphal segments. Lamellae edges fertile. Pleurocystidia and cheilocystidia absent. Pileipellis an ixocutis composed of slightly interwoven, incompactly arranged, somewhat gelatinized, hyaline, smooth, filamentous hyphae, 3–7 μm wide, sometimes inserted hyphae with yellowish to yellow smooth or incrusted intracellular pigment; the subpellis made up of compactly arranged, yellow, smooth or incrusted, intracellular- or parietalpigmented, filamentous hyphae, 3–10 μm wide; pileal trama composed of hyaline, filamentous, oblong, inflated hyphae, 5–18 μm wide. Stipitipellis a cutis composed of compactly arranged, slightly gelatinized, thinwalled, hyaline hyphae, 3–8 μm wide. Caulocystidia absent. Clamp connections absent.

Ecology and distribution: Scattered on soil in coniferous (viz., Pinus yunnanensis) or broad-leaved (viz., Fagaceae) forest, temporarily found in southwest

China, Jul to Sep.

Specimens examined: CHINA. YUNNAN PROVINCE: Deqin County, Baima Snow Mountain, singled on soil in Quercus semecarpifolia Smith forest, alt. 3344 m, 18 Aug 2018, S.P. Jian 223 (holotype KUNHKAS104518). CHINA, SICHUAN PROVINCE: Panzhihua City, Renhe District, Fangshan Mountain, 23 Jul 2011, T. Bau (HMJAU 24677). YUNNAN PROVINCE: Deqin County, Baima Snow Mountain, 18 Aug 2008, L.P. Tang 667 (KUNHKAS54898); Nanhua County, alt. 2166 m, 3 Aug 2009, Y.C. Li 1968 (KUN-HKAS59712); Kunming City, Kunming City, Yeyahu Resort, alt. 2100 m, 22 Sep 2012, S.X. Chen 81

(KUN-HKAS82076).

Notes: In sect. Clitopilus, C. yunnanensis is similar to C. rugosicepsbut but differs from this species by the often paxilloid to clitocyboid basidiomata and strongly gelatinized pileipellis with the pigment restricted in the subpellis.

Fig 1. Phylogenetic relationships among representative specimens of Clitopilus, Clitocella, and Clitopilopsis inferred from a multigene (28S, rpb2, tef1, and atp6) data set using both ML and BI methods (only the ML tree is shown). Bootstrap frequencies (>50%) and posterior probabilities (PP > 0.90) are shown on the supported branches. Sequences from type collections are marked, and altitude information of most specimens from KUN-HKAS is shown in the phylogram. New taxa are highlighted in red.