Macroscopic traits The thin-fleshed
cap is wide, arched or flattened, and more or less convex. The cap is smooth, matte and faintly ochre or faintly brown depending on humidity. The colours turn pale to a whiteish tone when the cap is dry. Mature fruiting bodies have a wavy and slightly grooved edge. The
lamella are strikingly tightly packed and almost exposed. In early stages, they are whiteish and later turn from a cream to leather-yellow or pink-brownish colour. The
spore powder is white. The
stem can be up to long, stiff, hollow, smooth and grooved along its length. It is red-brownish coloured and purple-grey and frosted with fine flakes. The tip of the stem is expanded, resembling a button, at the base of the gills. The base is covered with a white felty mycelium weave. The thin, tough flesh is cream-brownish and gives off a weak, aromatic mushroom scent. Its taste is described as mild. Amateurs would find it easy to confuse
Collybiopsis confluens with other types of mushrooms. Characteristic of this species are the narrow-standing lamellae, the thin-fleshed, reddish-brown and quickly-fading cap and the tough, gristly stem, which is usually noticeably hairy and quite long in relation to the diameter of the cap. The tufted growth is also typical for this species.
Microscopic traits The smooth,
inamyloid spores are 7–10 μm long and 3.5–4.2 (–5) μm wide. They are slightly tear-shaped, ellipsoid or spindle shaped. They are not cyanophilic, meaning that they cannot be dyed with
methyl blue. The club-shaped,
basidia containing four spores are 22.4–26.6 μm × 5–7 μm big.
Pleurocystidia are absent, but there are many 27.5–70 μm long and 2.8–5.6 μm wide
cheilocystidia. They are unevenly club- or cylinder-shaped and twisting. In some instances, they can be unevenly battered or branched like coral. The inamyloid Lamellartrama is parallel to interwoven. The
hypha are 3.5–7.8 (–14.8) μm wide, smooth, thin-walled and translucent. They partially contain strongly refractive lipid droplets. The Huttrama is inamyloid and loosely interwoven. The Hyphen are 5.5–13.2 μm wide. The skin of the cap (
Pileipellis) is only slightly differentiated and consists of crawling, branched, and radially orientated hyphen. The hyaline and thin walled cells are 2.8–7 μm wide and mostly smooth. Occasionally, they can be spirally and unevenly encrusted by a fine, faint yellow-brown pigment.
Clamp connections are present in all tissues.
Gymnopus peronatus can be similar. This also has lamella far apart from each other, yellow lamella when the mushroom is young, light brown lamellae when the mushroom is old, tastes burning hot and grows fewer tufts. == Distribution ==