pro·​thal·​lus | \ (ˌ)prō-ˈtha-ləs How to pronounce prothallus (audio) \

Definition of prothallus

1 : the gametophyte of a pteridophyte (such as a fern) that is typically a small flat green thallus attached to the soil by rhizoids
2 : a greatly reduced structure of a seed plant corresponding to the pteridophyte prothallus

Illustration of prothallus

Illustration of prothallus

prothallus 1: 1 antheridium, 2 archegonium, 3 rhizoid

First Known Use of prothallus

1854, in the meaning defined at sense 1

History and Etymology for prothallus

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The first known use of prothallus was in 1854

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Cite this Entry

“Prothallus.” Dictionary, Merriam-Webster, Accessed 24 Sep. 2020.

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