Gerronema pubescence Ming Zhang & W. X. Zhang, 2025

Gerronema pubescence Ming Zhang & W. X. Zhang sp. nov.

Figs 4 View Figure 4 , 5 View Figure 5

Diagnosis.

Distinguished from other Gerronema species by the combination characters of the pastel grey pileus covered with pubescence when young, yellowish white to pale yellow lamellae are paler towards the margin, the absence of cheilocystidia, and the narrow cylindrical to utriform pleurocystidia.

Holotype.

China • Guangdong Province: Huizhou City, Xiangtou Mountain Nature Reserve ; 23°26'N, 114°37'E; 335 m asl.; 19 September 2023; Hao Huang and Wei-Xin Zhang ( GDGM 94001 About GDGM ). GoogleMaps

Etymology.

pubescence (Latin), referring to the species pileus usually covered with pubescence when young.

Description.

Pileus 12–70 mm broad, hemispherical to plano-convex, depressed at center, grey (1 E 1), covered with pubescence when young, white to yellowish white (1 A 1–2) with age, grey to greyish brown (5 E 2–3, 6 C 1–2) at center, shallowly sulcate, surface dry, glabrous or pubescent, distinctly radially striped with grey to brownish orange (4 C 1–2, 6 C 2–3) lines, margin inflexed to reflexed. Lamellae subdecurrent, subdistant, ventricose, even, yellowish white to pale yellow (4 A 2–3), white (4 C 1) towards margin, with 1–5 lamellulae. Stipe 15–40 × 2–7 mm, central, cylindrical, hollow, white (1 A 1) to grey (1 C 1), covered with white granulose or fibrils. Odor and taste not recorded.

Basidiospores (6) 6.5–8 × (3.5) 4–4.5 μm, L m = 7.13 ± 0.57 µm, W m = 4.08 ± 0.29 µm, Q = (1.5) 1.56–2, Qm = 1.75 ± 0.18, ellipsoid to oblong, smooth, thin-walled, hyaline, guttulate, inamyloid. Basidia 24.5–39 × 5–7.5 μm, clavate, thin-walled, hyaline, 2 - or 4 - spored, with sterigmata 2.5–5 µm long. Cheilocystidia absent. Pleurocystidia 40–104 × 8.5–12.5 µm, narrowly cylindrical to lageniform, thin-walled, hyaline. Lamellar trama regular to subregular, hyphae 3.5–26.5 μm wide, thin-walled, hyaline. Pileipellis a cutis, hyphae 3–25 μm wide, smooth, hyaline; pileocystidia 39–100 × 10–21 μm, oblong to narrowly clavate, apex sometimes rostrate, thin-walled, greyish brown pigmented in KOH. Pileus trama regular to subregular, sarcodimitic. Stipitipellis a cutis, hyphae 2.5–38.5 μm wide, smooth, thin-walled, hyaline; caulocystidia 38.5–84.5 × 8.5–19 μm, narrowly cylindrical to clavate, thin-walled, hyaline. Stipe trama regular, sarcodimitic. Clamp connections present in all tissues.

Habit and distribution.

Scattered or caespitose on the rotten wood in broad-leaved forests. Currently only known from the type locality in China.

Additional specimen examined.

China • Guangdong Province: Zhaoqing City, Dinghu Mountain Nature Reserve ; 23°10'43"N, 112°33'10"E; 150 m asl.; 9 April 2024; Ming Zhang, Guo-Rui Zhong, and Wen-Xiao Xia ( GDGM 93936 About GDGM ) GoogleMaps .