Laccaria guizhouensis Jing Wang bis & Yi H. Yang, in Cao et al., Fungal Diversity 132: 531 (2025)

Index Fungorum number: IF 853733; Mycobank number: MB 853733; Facesoffungi number: FoF 17112; Figs. 1, 2

Etymology – referring to the type locality.

Holotype – HGASMF01-10872.

Pileus medium-sized, 25–35 mm diam., hemispherical to campanulate, orange white (5A2-6A2) to pinkish white or reddish white (7A2), concolorous finely hairy-scaly, roughened or scaly at the center; margin thin, wavy and slightly striate. Lamellae 3–5 mm deep, adnate to free, arcuate, distant, pastel red (8A4-8A5); lamellulae attenuate. Stipe 34–45 × 2–3 mm, central, cylindrical, basal mycelium absent; surface grayish red (8B4-8B5), subglabrous, with inconspicuous longitudinal stripes. Spore print not obtained.

Basidiospores (6.0–)6.5–7.6–8.7(–9.5) × (5.0–)5.5–6.4–7.0(–7.5) µm, Q = 1.0–1.18–1.38(–1.45), Qm = 1.18 ± 0.09, subglobose to broadly ellipsoid, rare globose and ellipsoid, echinulate, spines up to 2.0 µm in length, echinulae up to 3.0 µm high; Basidia (21–)25–31–35(–41) × 8–10(–11) µm, clavate, hyaline, thin-walled, 2- to 4-spored; sterigmata 3–7 µm long. Pleurocystidia and Cheilocystidia (12–)18–38(–42) × 3–11 µm, similar, hyaline, smooth, flexuous, subcylindrical to narrowly-cylindrical. Pileus trama interwoven, hyphae 2–6 µm wide, with a pale yellow wall pigment. Pileipellis a cutis, 5–22(–28) µm diam thickness, thin-walled, hyaline, hyphae 3–8 µm diam. Clamp connections present in all hyphae.

Material examined – CHINA, Guizhou Province, Qiannan Prefecture, Duyun City, hahe Factory, 26.37N 107.37E, 1077 m asl, 21 nov. 2020, Chun-Ying Deng, dcy2973 (HGASMF01-10872, holotype); Qiannan Prefecture, Duyun City, near Qingshan Factory, 26.37N 107.36E, 1154.4 m asl, 21 nov. 2020, Chun-Ying Deng, dcy2991 (HGASMF01-10854).

GenBank – HGASMF01-10872: PP733954 (ITS); HGASMF01-10854: PQ805232 (ITS).

Notes – Laccaria guizhouensis is phylogenetically related to L. salmonicolor A.W. Wilson & G.M. Muell. and L. versiforma H.J. Cho & Y.W. Lim (Fig. 2). However, there are clear morphological differences, with L. guizhouensis having smaller pleurocystidia and cheilocystidia [(12–)18–38(–42) × 3–11 µm], and a pinkish white pileus color. In addition, L. versiforma has globose basidiospores with smaller echinulae which are 1 µm long and 0.8–1 µm wide at base, bigger basidia 41–55 × 10–14 µm and hyaline lamellar trama hyphae (Cho et al. 2018); L. salmonicolor has copious basal mycelium on the stipe, bigger basidia 39–52 × 12–14 µm (Wilson et al. 2013).

Figure 1 – Laccaria guizhouensis. a Basidiomata. b basidiospores. c Basidia. d Pleurocystidia. e Cheilocystidia. f Clamp connection. g Pileipellis. Scale bars: c–g = 10 µm.

Figure 2 – Maximum Likelihood tree based on ITS sequences, bootstrap values greater than 50% are shown around nodes. New species are shown in bold.