thallus

thal·lus

noun \ˈthal-əs\

plural thal·li \ˈthal-ˌī, -ˌē\ or thal·lus·es

Definition of THALLUS

: a plant or plantlike body (as of an alga, fungus, or moss) that lacks differentiation into distinct members (as stem, leaves, and roots) and does not grow from an apical point