protonema

American  

[proh-tuh-nee-muh] / ˌproʊ təˈni mə /

noun

Botany.

plural

protonemata

1. a primary, usually filamentous structure produced by the germination of the spore in mosses and certain related plants, and from which the leafy plant which bears the sexual organs arises as a lateral or terminal shoot.

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protonema British  

/ ˌprəʊtəˈniːmətəl, -ˈnɛmətəl, ˌprəʊtəˈniːmə /

noun

1. a branched threadlike structure that grows from a moss spore and eventually develops into the moss plant

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protonema Scientific  

/ prō′tə-nē′mə /

plural

protonemata

1. The green filamentous or flat, thallus-like structure that grows from the germinated spores of liverworts and mosses and eventually gives rise to a mature gametophyte.

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Other Word Forms

• protonemal adjective

Etymology

Origin of protonema

1855–60; < New Latin < Greek prōto- proto- + nêma thread

Example Sentences

Usually the protonema is filamentous and ceases to be evident after the plants have developed.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria" by Various

The moss-plants arise from single projecting cells, and numerous plants may spring from the protonema developed from a single spore.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria" by Various

Besides this, gemmae may be formed on the protonema, on the leaves or at the apex, and some mosses have specialized shoots for their better protection or distribution.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria" by Various

For example, pieces will often break off from the tangled mass or protonema below, and, starting on their own account, form other thread masses.

From Through Magic Glasses and Other Lectures A Sequel to The Fairyland of Science by Buckley, Arabella B.

In addition to the leaves the stem often bears hair-like structures of different kinds, some of which correspond to modified branches of protonema.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria" by Various