thallus

[ thal-uhs ]

/ ˈθæl əs /

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noun, plural thal·li

[thal-ahy], /ˈθæl aɪ/, thal·lus·es.Botany, Mycology.

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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Origin of thallus

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

Words nearby thallus

thallium sulfate, thallo-, thalloid, thallophyte, thallous, thallus, thalweg, Thamar, Thames, Thames River, thamin

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use thallus in a sentence

In these there is a thallus which starts from a central point and continually divides in a forked or dichotomous manner.
Scientific American Supplement, Vol. XXI., No. 531, March 6, 1886|Various
The plant-body of a sea weed is called a thallus, and differs considerably in the various species.
The Sea Shore|William S. Furneaux
Another method is by the agency of little spores (zoospores) that are produced at the edges or extremities of the thallus.
The Sea Shore|William S. Furneaux
They are many times forked in the same plane, which produces a flat thallus.
The Sea-beach at Ebb-tide|Augusta Foote Arnold

The structure of the thallus may serve to represent that of most of the Lichens.
An Elementary Text-book of the Microscope|John William Griffith

British Dictionary definitions for thallus

thallus

/ (ˈθæləs) /

noun plural thalli (ˈθælaɪ) or thalluses

the undifferentiated vegetative body of algae, fungi, and lichens

Derived forms of thallus

thalloid, adjective

Word Origin for thallus

C19: from Latin, from Greek thallos green shoot, from thallein to bloom

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for thallus

thallus

[ thăl′əs ]

n. pl. thal•lus•es

A plant body or fungus undifferentiated into stem, root, or leaf.

Scientific definitions for thallus

thallus

[ thăl′əs ]

Plural thalli (thăl′ī)

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.