under Populus tremula, Salix caprea, Picea abies
on soil, spore size Me = 7.6 × 7.1 µm ; Qe = 1.1. My thinking was Pseudotomentella tristis, but in 'Fungi of Temperate Europe' description says there are no clamps. "Nordic Macromycetes" key says Pseudotomentella is only growing on wood. Any help will be very much appreciated.