Osteina is a fungal genus in the family Dacryobolaceae.
The genus was circumscribed by mycologist Marinus Anton Donk in 1966, with Polyporus obductus as the type species.
Catalogue of Life lists 3 accepted species:[1]
Osteina is characterized by fruit bodies that are sessile to stipitate, which are bone hard when dry. It has a monomitic hyphal system, containing only generative hyphae with clamps. The spores are hyaline and thin-walled, and are inamyloid and acyanophilic. Osteina causes a brown rot in gymnosperm wood.