Protostropharia semiglobata, commonly known as the dung roundhead, the halfglobe mushroom, or the hemispheric stropharia, is an agaric fungus of the family Strophariaceae. A common and widespread species with a cosmopolitan distribution, the fungus produces mushrooms on the dung of various wild and domesticated herbivores. The mushrooms have hemispherical straw yellow to buff-tan caps measuring 1–4 cm (0.4–1.6 in), greyish gills that become dark brown in age, and a slender, smooth stem 3–12 cm (1.2–4.7 in) long with a fragile ring.