protonema

American  

[proh-tuh-nee-muh] / ˌproʊ təˈni mə /

noun

Botany.

protonemata plural

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 /

protonemata plural

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

Derived Forms

• protonemal
  adjective

Inflected Forms

Nouns

• protonemata
  plural

Etymology

Origin of protonema

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

Example Sentences

See Examples For:

protonema

The protonema is not persistent, and the plants are well developed, resembling those of Pleuridium.

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

The protonema is always a well-marked stage in the life-history.

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

Vegetative propagation is widely spread in the mosses, and, as mentioned above, a protonema is always formed in the development of the new plant.

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

A filamentous protonema is first developed, some of the branches of which are exposed to the light and contain abundant chlorophyll, while others penetrate the substratum as brown or colourless rhizoids.

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