Spore
From Memory Alpha, the free Star Trek reference.
A spore is a structure used by some fungi and plants in order to reproduce themselves asexually.
In April of 2151, Commander Charles Tucker and Subcommander T'Pol were exposed to protocystian spores on the planet Rigel X. (ENT: "Broken Bow")
The following year, Phlox examined Travis Mayweather to ensure that he was not carrying protocystian spores. (ENT: "Singularity")
In 2364, members of the Omicron colony were infected by Omicron spores on the Omicron Ceti III. Three years later, the USS Enterprise arrived at the planet, and the crew was infected by the spores, but the actions of Captain Kirk were able to save them. (TOS: "This Side of Paradise")
In 2376, The Doctor sent Tom Paris and Neelix to the Wyanti system to gather spores that could be used to grow antiviral proteins. (VOY: "Live Fast and Prosper")
