Definitions

1. noun

A thallus is the vegetative part of a plant, especially a non-vascular plant such as a liverwort or moss, that bears the leaves or branch-like structures.

“The thallus of the liverwort was a flat, green structure that grew on the bark of the tree.”

2. noun

In fungi, a thallus is the main body of the organism that is responsible for food production and growth.

“The thallus of the fungus was a mass of branching hyphae that filled the entire container.”