This saprotrophic small gill fungus grows prolifically in large clumps on stumps, dead roots or rotting trunks of broadleaved trees.

[1][2] The specific epithet is derived from the Latin fascicularis 'in bundles' or 'clustered',[3] referring to its habit of growing in clumps.

[5] The stipe is 3–10 cm (1+1⁄8–3+7⁄8 in) tall and 4–10 mm wide,[4] light yellow, orange-brown below, often with an indistinct ring zone coloured dark by the spores.

[5] Hypholoma fasciculare has been used successfully as an experimental treatment to competitively displace a common fungal disease of conifers, Armillaria root rot, from managed coniferous forests.

[10] In humans, symptoms may be delayed for 5–10 hours after consumption, after which time there may be diarrhea, nausea, vomiting, proteinuria and collapse.

The autopsy of one fatality revealed fulminant hepatitis reminiscent of amatoxin poisoning, along with involvement of kidneys and myocardium.