Purple-spored Puffball (Calvatia cyathiformis) is a large mushroom found from July to November in prairies, pastures, lawns, and other open grassy areas. It grows on the ground and obtains its nutrients from decaying organic matter. It is widespread and occasional to locally common in eastern North America and the Great Plains. In the summer it appears as a white, rounded or pear-shaped puffball and is difficult to distinguish from several similar species. In the fall it turns dull purple, eventually rupturing to reveal a distinctive purple spore mass. It is edible in the summer when the flesh is white and solid.
The thin skin and mushy (while darkening) spore mass distinguish puffballs, which are edible, from earthballs, some of which are poisonous. The purple spores distinguish this species from all other puffballs in found in Minnesota.