Mycelium spore
Mycelium spores were a type of harmless spore derived from the mycelium of some types of fungi.

Mycelium spores harvested from the species Prototaxites stellaviatori were used in the experimental spore drive. These spores derived from a sample obtained by Paul Stamets. () The spores enabled access to the mycelial network. These spores might also be referred to as "mycelial spores", "fungal spores", or just spores. () They were described as clean and renewable. ()

Large amounts of these spores packed together might create hyper-gravitational and magnetic fields. The spores were attracted to a dark matter component in an Interstellar asteroid encountered by Discovery. () Sufficiently high concentrations of mycelium spores might also interact catastrophically with cosmic gases such as existed in the Yridia Nebula. ()

All personnel working around the spore drive were inoculated. () The spores were infused with an argon-xenon mixture to slow decay. ()

Spores from the Terran Empire universe were theorized to be different from the ones used by Discovery. ()

Biology