Collybiopsis melanopus

description

Pileus 12 – 20 mm diam., convex, expanding to plano-convex, rugulose-striate surface dull, dry, glabrous, disc brownish orange (7 C 5 – 7), margin paler to light orange (6 A 3 – 4) to beige (5 A 3). Context up to 1 mm thick, soft. Lamellae adnate, close to sub distant with 2 – 3 series of lamellulae, narrow, pale cream (4 A 3). Stipe 21 – 38 × 1.5 – 2 mm, central, cylindrical to tapering upwards, fistulose-stuffed, tough, sub insititious; surface dull, dry, white-pruinose overall, apex brownish grey (5 – 6 C 3), base dark brown to black; rhizomorphs absent. Odor and taste indistinct. Basidiospores [25 / 1 / 1] 7 – 8.5 × 3.5 – 4.5 μm, [x ̄ = 7.72 ± 0.56 × 3.9 ± 0.28 µm, Q = 1.75 – 2.43, Q m = 1.98 ± 0.19], ellipsoid, smooth, hyaline, inamyloid, thin-walled. Basidia 23 – 30 × 5 – 7 μm, clavate, smooth, hyaline, inamyloid. Pleurocystidia absent. Cheilocystidia 43 – 68 × 21 – 28 μm, clavate to fusiform, broadly obtuse, hyaline, inamyloid, thin-walled. Pileipellis a cutis of radially arranged, repent hyphae 4 – 6 μm, cylindrical, non-diverticulate, smooth or brown-incrusted, hyaline, inamyloid, non-gelatinous, thin-walled; terminal cells undifferentiated. Pileus trama radially arranged

Five new records of Collybiopsis (Agaricales, Omphalotaceae) in Thailand: a significant addition to the species diversity and global distribution of the genus