Hygrophorus brunneodiscus 2020

Hygrophorus brunneodiscus C.Q. Wang & T.H. Li 2020

Fungal Names: FN 570664

Holotype: China, Hunan Province, Zhangjiajie City, Zhangjiajie Campus of Jishou University, on the ground of a forest dominated by Quercus fabri and Q. serrata, elev. ca. 220 m, 29°8'24"N, 110°27'42"E, 26 May 2019, W.Q. Qin (GDGM73213, Holotype!).

Morphological description

Pileus 20–50 mm broad, hemispherical or conical with a slightly involute or slightly revolute margin when young, becoming convex with an expanded margin when mature, whitish to brownish as a whole, brownish-orange, light brown, yellowishbrown (5C4–5, 5D4–5, 5E5–8) at the disc (about one fourth part of the radius from the centre to the margin), becoming paler to greyish-yellow (4B3–4), greyish-white (4B1) or whitish outwards and white at the margin or with a white marginal zone of 1–2 mm wide, viscid, covered with a glutinous layer of transparent materials when wet. Lamellae short decurrent to decurrent, white, waxy, with 36–40 complete lamellae and 1–3 lamellulae between two complete lamellae; lamella edge concolorous, entire. Stipe 40–90 × 4–7 mm, cylindrical, hollow, nearly equal to slightly thinner at apex and tapering towards the base; pale yellow to greyish-yellow (4A3, 4B3), white to yellowish-white (4A2) at apex, sometimes white at base; sticky, covered with a layer of transparent materials when wet, easily-sticking debris on the slime layer, usually fibrillose or with scattered white fibrillose dots at apex. Context thin, white to light brown, with slight fishy odour.

Basidiospores (6.5)7–9(9.5) × 4–5.5(6) µm [mean length = 7.6 µm, mean width = 

4.6 µm], Q = (1.3)1.4–2(2.1), Qm = 1.68, ellipsoid to oblong, smooth. Basidia 32– 48 × 6–8.5 µm, Q = 4.1–6.6, Qm = 5.3, clavate, thin-walled, 4-spored, with sterigmata 5.5–7(9) µm long. Pileipellis an ixotrichoderm, composed of septate cylindrical hyphae, covered with a gelatinous layer; hyphae thin-walled, 2.5–5 µm wide, slightly yellowish and glutinous in KOH. Hymenophoral trama divergent, composed of septate, thin-walled and cylindrical hyphae; hyphal cells 45–70 × 6–10 µm, hyaline. Clamp connections present.

Habitat: Solitary to scattered, on the ground of subtropical broad-leaf forest dominated by Quercus.

Distribution: So far only known from Hunan Province in South Central China.

GenBank Accession: ITS: MN378318.

Notes:

Reference: Wang C-Q, Li T-H, Zhang M et al.(2020) Hygrophorus subsection Hygrophorus (Hygrophoraceae, Agaricales) in China. MycoKeys 68: 49–73. https://doi.org/10.3897/mycokeys.68.53264

Hygrophorus brunneodiscus. a, b Basidiomata (GDGM73213, Holotype) c, d Basidiomata (GDGM75489) e Basidiospores (GDGM73213) f Basidia (GDGM73213) g Elements of pileipellis (GDGM73213). Scale bars: 2 cm (a–d).