Protostropharia semiglobata, commonly known as the dung roundhead, the halfglobe mushroom, or the hemispherical 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.

A delicate ring forms an annular zone on the mid to upper portion of the stem that may be darkened from spore deposits.

The thick-walled spores are ellipsoidal, smooth, and have a small apical germ pore; they measure 16.1–19.0 by 8.8–11.0 μm.

[8] Other mushrooms that resemble Protostropharia semiglobosa include Stropharia dorsispora, S. luteonitens, and Panaeolus semiovatus.

[10] A saprobic species, the fungus fruits in small groups on dung, in soil containing manure, on lawns, grasslands, or in livestock corrals.

[8] It has been recorded on the dung of a variety of wild and domesticated herbivores and ungulates, including rabbit, sheep, cow, buffalo, moose, bear, and wallaby.