Heliocybe villosa Ming Zhang & T.H. Li, 2018

Heliocybe villosa Ming Zhang & T.H. Li sp. nov.

Fungal Names: FN570533.

Etymology: The epithet ‘ villosa ’ (Lat.) refers to the villous pileus surface.

Diagnosis: Differs from H. sulcata by the villous pileus and smaller basidiospores (6.5)7–9 × 3–3.5(–4) μm.

Type:— CHINA. Guangdong Province: Shaoguan City, Nanling National Nature Reserve , in a mixed broadleaf-conifer forest, at 113°03′ E, 24°45′ N, 800 m asl, 2 August 2017, Ming Zhang ( GDGM45926 , holotype!) GoogleMaps .

Macroscopic characters: —Basidiomes small. Pileus 2–4 cm, moderately fleshy, hemisperical to obtusely convex when young, then expanding to applanate with age, with a more or less umbonate center, brownish yellow, brownish orange, light brown to brown (5C8–7C8, 5D8–7D8), usually darker at center and paler near the margin, surface dry, densely covered with more or less radially arranged brownish yellow (5C8), brownish orange (6C8) light brown (6D8) to brown (6E8–7E8) villous hairs which usually agglutinate to small squamules on paler creamy white to yellowish brown background, often paler with age. Context of pileus thin, white, 2–4.5 mm thick at center. Lamellae close, with 50–60 complete lamellae each pileus, 3–4.5 mm wide, unequal, lamellulae of different length frequent, serrated at edge, adnate to subdecurrent to the stipe, white or cream. Stipe 3–5 cm long, 3–5 mm wide, central, equal or with a slightly swollen base, surface dry, white or nearly so and with teeth from the decurrent lamellae at apex, becoming brown (5E8–7E8), grayish brown (5F3–9F3), dark brown to reddish brown (5F8–9F8,) downwards, densely with villous hairs which are white or whitish at first and then becoming brownish orange to brown (similar to those on pileus or even darker), without a ring, solid and tough.. Odor and Taste indistinct.

Microscopic characters:—Basidiospores [80/4/2] (6.5)7–9 × 3–3.5(–4) μm, Q = (1.86–)2–2.67(–2.83), Qm = 2.34 ± 0.24, smooth, broadly cylindric, subreniform to botuliform, hyaline, inamyloid, thin-walled. Basidia 18–26 × 5–7 μm, clavate, predominantly 4-spored, infrequently 2-spored, sterigmata 2–3.5 μm long, hyaline. Pleurocystidia 22–33 × 5–8 μm, infrequent, barely projecting, fusiform, hyaline, thin-walled. Cheilocystidia not observed. Hymenophoral trama bilateral with thin-walled branched hyphae in 5–10 μm wide, hyaline in 5 % KOH. Pileipellis a trichodermium of repent to upswept or suberect hyphae 4–6 μm wide, narrowly clavate or subcylindrical, thin- to slightly thickwalled, containing yellow brown pigment, terminal cell up to 200 μm long. Stipitipellis a layer of repent to upswept or suberect hyphae 3–6 μm wide, containing yellow brown pigment as pileipellis. Stipe trama composed of parallel branched hyphae 3–7 μm wide, hyaline in 5 % KOH. Clamp connections absent in all tissues.

Habit, habitat and distribution:—Saprotrophic, caespitose to scattered on dead and decaying coniferous wood ( Pinus kwangtungensis Chun ex Tsiang ). So far only known from Guangdong Province in southern China.

Additonal material examined:— CHINA, Guangdong Province: Shaoguan City, Nanling National Nature Reserve , in a mixed broadleaf-conifer forest with P. kwangtungensis , 113°03′ E, 24°45′ N, alt. 800 m asl, 2 August 2017, Bin Song ( GDGM49411 ) GoogleMaps .