Myriostoma coliforme (Dicks.) Corda (1842)
Commonly called the Saltshaker earthstar, or in some areas, the Pepper Pot.
This fungus features a roundish ball called a head or a peridium containing spores. This ball sits on small stalks on top of star-like rays. When immature or dry, the rays (also called the outer peridium or exoperidium) enclose the endoperidium (inner peridium). When the basidiocarp gets wet, the exoperidium splits and folds back, forming the star-shaped structure. The inner peridium remains closed and this is where the spores are formed.
Unlike true puffballs, the basidia where the spores grow are not arranged in a hymenium. Instead the basidia form throughout the entire inside of the head. This spore mass is called the gleba. The gleba becomes powdery with age and the spores are dispersed through holes in the peridium called mouths or pores.
When the mushroom gets dry the star-like rays will fold back up around the endoperidium until it rains again, then they fold back out and the rain droplets can hit the walls of the endoperidium. The force of the droplets ejects spores out of the pores. This behavior allows the fungus to disperse its spores during moist conditions which increases the chance that they will be able to germinate.
Etymology: From Latin, “like a colander”
Previously known as:
Lycoperdon coliforme Dicks. (1776)
Geastrum coliformis (Dicks.) Pers. (1801)
(Taxonomy from Index Fungorum )