Prototaxites stellaviatori was a species of fungus.
In 2256, this species was grown in the cultivation bay aboard the USS Discovery. Its mycelium spores were harvested for use in the experimental spore drive of the Federation starship. (DIS: "Context Is for Kings")
Stellaviatori comes from the Latin roots stella ("star"), and viator ("traveller"), thus hinting at the species' properties.