A fungus was a eukaryotic lifeform, which lacked vascular tissue and chlorophyll. Fungi can be unicellular or multicellular.
The leola root is a dark yellow root vegetable native to the Delta Quadrant that is covered in mildew (a variety of fungus). (VOY: "State of Flux")
Ledonian soil contains mycorrhizal fungus that helps plants on Ledonia III retain water. (DS9: "The Wire")
In 2246, an exotic fungus destroyed most of Tarsus IV's food supply. (TOS: "The Conscience of the King")
In 2373, the pah-wraith possessed Keiko O'Brien claimed she had only seen some beautiful and botanically fascinating fungi in the Fire Caves, but no pah-wraiths. (DS9: "The Assignment")
During their attempt to teach an infant Changeling how to shapeshift, Doctor Mora suggested that he and Odo expose the Changeling to simple lifeforms such as algae, fungus and then invertebrates. (DS9: "The Begotten")
Tri-nucleic fungus can be used to manufacture ketracel-white. (DS9: "Statistical Probabilities")
Types of fungi