Cibaomyces glutinis Zhu L. Yang, Y.J. Hao & J. Qin, sp. nov.

Figs. 2–4

MycoBank: MB 807467

Etymology: glutinis refers to the glutinous pileus and stipe.

Type:— CHINA. Yunnan Province: Jizu Mountain, Binchuan County, 25°57'39''N, 100°23'31''E, elev. 2200 m, 3 August 2013, Jiao Qin 725 (HKAS80855, holotype!) .

Basidiomata (Fig. 2a–b) small to medium-sized. Pileus 3–4.5 cm, convex to applanate, strongly glutinous, dirty white to brownish to grayish (5B2–5B3, 5C2–5C3), finely rugose, often with brownish irregularly-shaped dots; center slightly darker. Lamellae adnate to sinuate or slightly decurrent, subdistant, with lamellulae, L = 20–25, l = 1–3, thick, dirty white to cream, sometimes with reddish to brownish spots, transversely veined, with lamellae frequently anastomosing; lamellar edge rusty brown to brownish. Context 2–3 mm thick, dirty white to brownish, unchanging in color when cut. Stipe 6–9.5 × 0.3–0.8 cm, subcylindrical, enlarged at ground line, surface dirt white to grayish, sticky, densely covered with brownish felted squamules but nearly white at apex; pseudorhiza dirty white. Taste mild; odor indistinct.

Lamellar trama ± regular, composed of branching, nearly colorless and hyaline, slightly thick-walled (≤ 1 µm thick), filamentous to inflated hyphae 3–20 µm wide. Subhymenium composed of 3–5 µm wide frequently branching hyphal segments. Basidia (Fig. 3d) 50–70 × 13–15 µm, 4-spored, thin-walled, colorless hyaline, sometimes with yellowish brown contents; sterigmata up to 10 µm in length; basidioles clavate to subfusiform with subacute apex. Spores (Fig. 3b) [55/2/2] (9) 10.5–14 (15) × (8.5) 9–11.5 (12.5) µm, Q = (1.0) 1.05–1.24 (1.30), Qm = 1.14 ± 0.07, subglobose to broadly ellipsoid, thin-walled, colorless and hyaline, sometimes with brownish to brown contents, non-amyloid, non-dextrinoid, cyanophilous, non-metachromatic, with ca. 25 spines conspicuous, 2–4(5) µm high and 1.5–2 µm broad at base, hollow, conical to subcylindrical spines with obtuse apex. Lamellar edge sterile, composed of crowded cheilocystidia; cheilocystida (Fig. 3c) 50–130 × 4–8 µm, numerous, narrowly clavate, subcylindrical to cylindrical, often with a round to subcapitate apex, with brownish, brown to chocolate brown intracellular pigment, often incrusted brown substances. Pleurocystidia absent. Pileipellis (Fig. 3a) an ixohymeniderm 40–60 µm thick, composed of clavate, broadly clavate to sphaeropedunculate, brownish to brown intracellularly pigmented cells (20–50 × 10–30 µm) embedded in a gelatinized matrix with brown to dark brown crystalline material. Pileocystidia (Fig. 3a) abundant, subcylindrical to narrowly clavate, occasionally narrowly fusiform to lageniform, 40–80 × 4–8 µm, thin-walled, nearly colorless or with brownish to brown intracellular pigment, with apical parts often incrusted with brown, yellow-brown to ochraceous substances which are slowly soluble in KOH; apex narrowly rounded, rarely acute. Stipitipellis composed of vertically arranged, branching, nearly colorless and hyaline, slightly thick-walled (ca. 0.5 µm thick), filamentous hyphae 3–15 µm broad. Caulocystidia (Fig. 3e) 50–100 × 3–8 µm, numerous and crowded, evenly distributed, narrowly clavate to subcylindrical, thin- to slightly thick-walled (ca. 0.5 µm thick), often with a round apex, with dark brown to yellow-brown intracellular pigment, occasionally nearly colorless and hyaline, often incrusted with brown to yellow-brown substances. Chlamydospores not observed. Clamp connections abundant in every part of basidioma. Habitat and known distribution: fruiting in broad-leaved forests dominated by Fagaceae, on buried rotten wood; in summer at elev. 1000–2200 m in southwestern China and northern Japan.

Additional specimen examined: JAPAN. Tomakomai: Hokkaido, elev. 1000 m, on buried rotten wood, 13 September 2011, Zhu Liang Yang 5553 (HKAS71038!) .