- a simple vegetative body undifferentiated into true leaves, stem, and root, ranging from an aggregation of filaments to a complex plantlike form.
Origin of thallus
1820–30; < New Latin < Greek thallós young shoot, twig
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for thalli
Other algae doubtless sometimes occur in the thalli of Peltigerae.Ohio Biological Survey, Bull. 10, Vol. 11, No. 6
Bruce Fink and Leafy J. Corrington
These structures cannot then be produced from the product of a single spore nor even from the thalli derived from any two spores.
- the undifferentiated vegetative body of algae, fungi, and lichens
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
Word Origin and History for thalli
Latin, from Greek thallos "green shoot, twig," related to thalia "abundance," thalos "scion, child," ultimately from PIE root *dhal- "to bloom" (cf. Old Irish duilesc, a type of algae).
Online Etymology Dictionary, © 2010 Douglas Harper
- A plant body or fungus undifferentiated into stem, root, or leaf.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- 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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.