thallus

American  

[thal-uhs] / ˈθæl əs /

noun

Botany, Mycology.

plural

thalli, thalluses

1. a simple vegetative body undifferentiated into true leaves, stem, and root, ranging from an aggregation of filaments to a complex plantlike form.

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thallus British  

/ ˈθæləs /

noun

1. the undifferentiated vegetative body of algae, fungi, and lichens

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thallus Scientific  

/ thăl′əs /

plural

thalli

1. A type of body found among plants and fungi that is not differentiated into roots, stems, or leaves. Thalli are found among lichens, mosses, liverworts, and many algae, as well as the gametophyte generations of horsetails and ferns, which have rhizoids but not true roots.

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Other Word Forms

• thalloid adjective

Etymology

Origin of thallus

1820–30; < New Latin < Greek thallós young shoot, twig

Example Sentences

Foliose species have lobed, leaflike bodies, or thalli; you can see both their upper and lower surfaces, which are different colors.

From Seattle Times

The process of working out what things were often felt like trying to solve a recalcitrant crossword puzzle, particularly when it involved learning technical terms like scopulae and thalli.

From New York Times

Antheridia immersed in the thallus, covered with dentate scales.

From Project Gutenberg

These structures cannot then be produced from the product of a single spore nor even from the thalli derived from any two spores.

From Project Gutenberg

Piece of thallus of Parmelia conspersa, with section through an apothecium.

From Project Gutenberg