Panaeolus semiovatus var. semiovatus, also known as Panaeolus semiovatus and Anellaria separata, is a medium-sized buff colored mushroom/toadstool that grows on horse dung, and has black spores. While some guides list this species as edible, a few people experience gastric upset after consumption. Its common names are the shiny mottlegill, or egghead mottlegill.