Psathyrella delineata is a North American name, however North American sequences nest within European gossypina and are within the range of morphological variation of that species.
See
Wang, S. N., Hu, Y. P., Chen, J. L., Qi, L. L., Zeng, H., Ding, H., … & Yan, J. Q. (2021). First record of the rare genus Typhrasa (Psathyrellaceae, Agaricales) from China with description of two new species. MycoKeys, 79, 119.
Örstadius et al 2015: Molecular phylogenetics and taxonomy in Psathyrellaceae (Agaricales) with focus on psathyrelloid species: introduction of three new genera and 18 new species
Moreau, P. A., & Padovan, F. (2003). Due specie lignicole spesso confuse: Psathyrella chondroderma e P. gossypina. Boll. Gr. Micol. G. Bres, 46(2), 5-14.
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.
Its not difficult to support the claim that they are on different evolutionary trajectories and both names can be used independently....