Wikipedia
Calostoma is a genus of 29 species of gasteroid fungi in the suborder Sclerodermatineae. Like other gasteroid fungi, Calostoma do not have the spore discharge mechanism associated with typical gilled fungi ( ballistospory), and instead have enclosed spore-bearing structures. Resembling round, orange to red gelatinous puffballs on thick stalks, species have been collected in regions of deciduous, temperate, tropical or subtropical forests. They have a worldwide distribution, including eastern North America, Asia, and Australasia. The common name given to some species, "prettymouth", alludes to the bright red fruit bodies with openings that may somewhat resemble lips.
The unusual fruit body structure has historically led mycologists to suggest various classification schemes based on presumed relationships to other puffball or "stomach mushrooms". Phylogenetic analyses performed in the 2000s show the genus to be evolutionarily related to the Bolete mushrooms. Calostoma species are ectomycorrhizal, forming symbiotic associations with trees from various families. The type species, Calostoma cinnabarinum, is ectomycorrhizal with oak.