prothallus

[ proh-thal-uhs ]
/ proʊˈθæl əs /

noun, plural pro·thal·li [proh-thal-ahy]. /proʊˈθæl aɪ/. Botany.

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Origin of prothallus

From New Latin, dating back to 1850–55; see origin at pro-2, thallus
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for prothallus

British Dictionary definitions for prothallus

prothallus

prothallium (prəʊˈθælɪəm)

/ (prəʊˈθæləs) /

noun plural -li (-laɪ) or -lia (-lɪə)

botany the small flat free-living gametophyte that bears the reproductive organs of ferns, horsetails, and club mosses. It is either a green disc on the soil surface or it is colourless and subterranean

Derived forms of prothallus

prothallic or prothallial, adjective

Word Origin for prothallus

C19: from New Latin, from pro- before + Greek thallus a young shoot
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

Scientific definitions for prothallus

prothallus
[ prō-thăləs ]

Plural prothalli (prō-thălī)

The gametophyte of homosporous ferns and some other plants. Prothalli have chlorophyll for photosynthesis, but they are not differentiated into roots, stems, or leaves. They are usually small, flat, and delicate. Prothalli develop from germinated spores, and they bear both archegonia for producing eggs and antheridia for producing sperm. See more at alternation of generations.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.