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.

---

protonema British  

/ ˌprəʊtəˈniːmətəl, -ˈnɛmətəl, ˌprəʊtəˈniːmə /

noun

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

---

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.

---

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

In this moss the filamentous protonema is capable of assimilation, but the leaves of the small plants are destitute of chlorophyll, so that they are dependent on the protonema.

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

The sexual generation is always a leafy plant, which is not developed directly from the spore but is borne on a well-marked and usually filamentous protonema.

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

The spore on germination forms a short filament which soon broadens out into the thalloid protonema.

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

The protonema is usually filamentous, and in some of the simplest forms is long-lived, while the small plants borne on it serve mainly to protect the sexual organs and sporogonia.

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

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