| Geastrum welwitschii | |
|---|---|
| |
| Left: type specimen; right: specimen collected in Florida, and kept at the herbarium of the Department of Agriculture, Washington | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Geastrales |
| Family: | Geastraceae |
| Genus: | Geastrum |
| Species: | G. welwitschii
|
| Binomial name | |
| Geastrum welwitschii Mont. (1856)
| |
| Synonyms | |
| |
Geastrum welwitschii | |
|---|---|
 | Glebal hymenium |
 | No distinct cap |
 | Hymenium attachment is not applicable |
| Lacks a stipe |
 | Spore print is brown |
 | Ecology is saprotrophic |
 | Edibility is inedible |
Geastrum welwitschii is a species of fungus in the earthstar family. First collected from Spain in the mid-19th century, the fungus is distributed in Europe, North America, and Bermuda.
When young and unopened, the fruit bodies resemble small spheres lying in the soil. As the mushroom matures, the thick leathery outer layer of tissue (the peridium) splits star-like to form a number of fleshy arms, which curve downward to reveal the inner spore sac that contains the fertile tissue known as the gleba. The spore sac has a narrow grooved opening at the top where the spores are released. Fully expanded, the fruit bodies are up to 35 mm (1+3⁄8 in) wide and 58 mm (2+1⁄4 in) tall.