Also growing abundantly from the Hügel are these. As best I can tell they are Coprinellus micaceus, AKA "mica cap", or some close relative. They probably tagged along on the logs buried beneath the mound. They've been popping up every 2-3 days or so for the past week and disintegrating just as quickly. I'm hoping the king stropharia I inoculated the mound with can compete and/or co-exist with them.