noun \ˈtha-ləs\
plural thal·li \ˈtha-ˌlī, -ˌlē\ or thal·lus·es

Definition of THALLUS

:  a plant body that lacks differentiation into distinct parts (as stem, leaves, and roots), does not grow from an apical point, and is characteristic of organisms formerly classified as thallophytes

Origin of THALLUS

New Latin, from Greek thallos, from thallein to sprout; akin to Armenian dalar green, fresh, Albanian dal I come forth
First Known Use: 1829


noun \ˈthal-əs\   (Medical Dictionary)
plural thal·li \ˈthal-ˌī, -ˌē\ or thal·lus·es

Medical 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


noun    (Concise Encyclopedia)

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.


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