Candolleomyces yunnanensis D.G. Zheng. & Karun., 2025

Zheng, De-Ge, Voto, Pietro, Tibpromma, Saowaluck, Lu, Wen-Hua, Han, Mei-Yan, Kumla, Jaturong, Suwannarach, Nakarin, Dai, Dong-Qin, Zhang, Li-Juan, Elgorban, Abdallah M., Chukeatirote, Ekachai & Karunarathna, Samantha C., 2025, Candolleomyces yunnanensis (Psathyrellaceae, Agaricales), a novel species from Yunnan Province, China, Phytotaxa 711 (3), pp. 281-292 : 287

Candolleomyces yunnanensis D.G. Zheng. & Karun. , sp. nov. FIGURE 2

Index Fungorum number: IF904057

Etymology: “ yunnanensis ” refers to the type locality, Yunnan Province, China.

Holotype: China, Yunnan Province, Qujing City , Malong County, on soil, 25°25′13′′ N 103°29′17′′ E, elev. 1,980 m, 13 June 2024, D.G. Zheng, ( ML7 = GMB-W1508 ).

Pileus 23–38 mm in diameter, parabolic or plane when young and convex-subumbonate when mature, slightly hygrophanous, bronze brown (5E5) to yellowish brown (5E4) at the center and brownish grey (5E2) to birch grey (5C2) towards the margin, forming a straight and regular margin. Veil white (5A1), fibrillose, rarely on the edge of the pileus, and gradually disappearing in maturity stages. Lamellae adnate to slightly adnexed, greyish red (10C4) to reddish grey (10B2). Stipe 44–87 × 3–5 mm, cylindrical, hollow, equal, slightly flexuous, white (5A1) to white grey (5B1), with a little white mycelium at the base. Annulus absent. Odour and taste were not determined.

Basidiospores (5.2–) 5.3–7.0(–7.4) × (2.8–) 3.0–4.3(–4.4) µm (avL= 6.22 µm, avW= 3.68 µm), Q = 1.45–2.05, Q m = 1.70, ellipsoid to oblong, pale brown to brown in water, and deepens in 5% KOH, smooth, with small germ pore. Basidia (15.8–) 16.3–25.3(–28.0) × (5.5–) 5.8–8.4(–8.6) µm, short clavate, hyaline, 4-spored, a few 2-spored, rarely unisterigmate, with granular content, in front view elliptic to oval, in side view adaxially flattened to slightly subphaseoliform. Cheilocystidia (27.9–) 28.5–49.9(–51.4) × (7.0–) 8.5–15.7(–16.1) µm, narrowly utriform, cylindrical to claviform, thin-walled, rarely with deposits, lageniform top, conical, hyaline. Pleurocystidia absent. Pileipellis a one to two-layered irregular epithelium composed of globose to subglobose or ellipsoid cells with 43–70 × 35–54 µm diameter, thinwalled, hyaline in 5% KOH. Clamp connection present.

Habitat: Scattered on the soil, among grasses and fallen leaves.

Distribution: Only known from Yunnan, China.

Additional specimen examined: China, Yunnan Province, Qujing City, Malong County, 25°25′28′′ N 103°28′49′′ E, elev. 1,973 m, 13 June 2024, S.C. Karunarathna, (QJ345 = GMB-W1509, paratype).

GenBank numbers: GMB-W1508: nrITS = PV590303, nrLSU = PV618426, tef -1α = PV640648. GMB-W1509: nrITS = PV590304, nrLSU = PV618427, tef -1α = PV640649.

Notes: In morphology, C. yunnanensis differs from C. shennongdingicus by longer stipes (44–87 × 3–5 mm vs. 34–53 × 3–5 mm), slightly smaller basidiospores and basidia, bigger cheilocystidia (28.5–49.9 × 8.5–15.7 µm vs. 29.8–40.5 × 9.5–13.3 µm), and, especially, larger pileipellis cells (43–70 µm vs. 19.8–29.5 µm). Candolleomyces shennongdingicus has a different color with pileus which is golden yellow (5B7) to golden brown (5D7) at the center and golden blonde (5C4) to nougat (5D3) toward the margin, and the lamellae are orange-grey (5B2) to grey (5D1). In addition, although both our collection and C. shennongdingicus are from China, C. shennongdingicus is found on the ground with rich humus in broad-leaved or deciduous coniferous forests in Hubei Province ( Han et al. 2024), while our collection was from the grassland of a deciduous broad-leaved forest in Yunnan Province. Based on this evidence, we identify our collection as C. yunnanensis sp. nov.

Figures

FIGURE 2. Candolleomyces yunnanensis (GMB-W1508, holotype). a Basidiomata. b Basidiospores. c Basidiospores are stained with 1% Congo red solution. d Basidia. e–f Cheilocystidia. g Pileipellis. Scale bars: a = 2 cm, b–f = 20 μm, g = 50 μm. b–g images in a 5% KOH solution. c–f are stained with a 1% Congo red solution.