Plant body of algae, fungi (see fungus), and similar simple, plantlike organisms. Composed of filaments or plates of cells, a thallus ranges in size from a single-celled structure to a complex treelike form. The photosynthetic and supportive cells tend to be organized linearly, but a thallus lacks such differentiated specialized structures as stem, leaves, and conducting tissue. Most thallus plants are currently classified as complex protists.
This entry comes from Encyclopædia Britannica Concise.
For the full entry on thallus, visit Britannica.com.
Seen & Heard
What made you look up thallus? Please tell us what you were reading, watching or discussing that led you here.