Termitomyces upsilocystidiatus

Pileus 5–11.3 cm diam., depressed, with large, obtuse umbo-shaped perforatorium, frequently cleaving toward margin; surface pale brownish grey (4B2–6C2–3), gradually slightly paler toward margin, glabrous. Lamellae free, 0.8–1.0 cm broad, crowded, white (1A1) to pinkish white with age; margins fimbriate, irregularly eroded to cleaved at places, concolorous, lamellulae in 1–2 tiers. Stipe 4.5–5.5 × 1.5–1.7 cm, central, cylindrical, with bulbous base up to 3 cm, exannulate, off-white, smooth, glabrous, solid. Pseudorrhiza cylindrical, tapering, white, longitudinally striate, solid, fibrous. Context white, up to 4 mm thick under perforatorium. Odour slightly fragrant. Taste sweet. Spore print pinkish.

Basidiospores [49/10/2] (4.8)4.9–5.56–6.7(6.8) × (3.5)3.6–3.74–4.1(4.2) μm, Q = 1.48 ± 0.11, ovoid to ellipsoid, thin-walled, hyaline. Basidia (18.0)18.5–21.5(24.0) × (5.8)6.0–7.3(8.0) μm, clavate to slightly flexuose with one, two or four sterigmata. Cheilocystidia 36.0–59.1 × 12.3–23.0 μm, typically Y-shaped, sometimes merely gibbose or triangular, thin-walled, hyaline. Pleurocystidia 45.6–76.9 × 19.8–38.6 μm, fusiform. Hymenophoral trama 131–205 μm wide, regular, thin-walled, hyaline hyphae, 6–13 μm wide. Hymenial layer 300–400 μm wide. Pileipellis a cutis 300–440 μm thick, of radially oriented hyphae, 15.0–18.0 μm wide. Pseudorrhiza context of thin-walled, hyaline hyphae, 9.3–12.0 μm wide. (Fig. 1)

MycoBank: MB 833137, Faces of Fungi: 06724

Holotype: CHINA. Yunnan Province, Dali prefecture, Nan-Jian county. 25°02.376’N, 100°30.174’E. 1,500 m a.s.l., 3 September 2016, collected by Hong-Yan Su (MFLU19-1289, holotype!).

Habitat and distribution: Gregarious to scattered, in plantation or forest, above subterranean termitaria. Currently known only from Yunnan Province, China.