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.

---

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 /

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.

---

Other Word Forms

• protonemal adjective

Etymology

Origin of protonema

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

Example Sentences

The protonema forms a flat, lobed, thalloid structure attached to the soil by rhizoids, and the plants arise from marginal cells.

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

In Sphagnum, Andreaea and some genera of the Bryales the protonema or some of its branches have the form of flat plates or masses of cells.

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

The social growth of the plants characteristic of many mosses is a result of the formation of numerous plants on the original protonema and on developments from the rhizoids.

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.