protonema

/proh-tuh-nee-muh/US // ˌproʊ təˈni mə //UK // (ˌprəʊtəˈniːmə) //

原子体,原子膜,原子宫,原子宫内膜

Definitions

n.名词 noun

1
plural pro·to·ne·ma·ta [proh-tuh-nee-muh-tuh]. /ˌproʊ təˈni mə tə/. Botany.
- : 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.

Erect branches may arise from the protonema, and gemmae may be developed on it.
In mosses (fig. 12) a filamentous growth, the protonema, is first formed, and the leafy plants arise upon this.
Usually the protonema is filamentous and ceases to be evident after the plants have developed.
The protonema forms a flat, lobed, thalloid structure attached to the soil by rhizoids, and the plants arise from marginal cells.
The spore on germination forms a short filament which soon broadens out into the thalloid protonema.