protonema
Quick Summary
The protonema is the initial, usually filamentous stage of the gametophyte in mosses and some liverworts. It develops when a spore germinates and precedes the more organized gametophyte plant. In mosses, the protonema is typically threadlike and highly branched, while in most liverworts and hornworts, it is reduced to just a few cells. This stage is comparable to the prothallus found in ferns. The protonema plays a crucial role in the life cycle of these plants, serving as the precursor to the gametophyte generation which produces the sex organs.12
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bryophyteForm and functionThe protonema, which grows directly from the germinating spore, is in most mosses an extensive, branched system of multicellular filaments that are rich in chlorophyll. This stage initiates the accumulation of hormones that influence the further growth of newly formed cells. When specific concentrations of the…
Read MoreThe protonema, which grows directly from the germinating spore, is in most mosses an extensive, branched system of multicellular filaments that are rich in chlorophyll. This stage initiates the accumulation of hormones that influence the further growth of newly formed cells. When specific concentrations of the…
Read More- bryophyteReproduction and life cycle
The protonema is usually threadlike and is highly branched in the mosses but is reduced to only a few cells in most liverworts and hornworts. The protonema stage in liverworts is usually called a sporeling in other bryophytes (see below Form and function).
Read MoreThe protonema is usually threadlike and is highly branched in the mosses but is reduced to only a few cells in most liverworts and hornworts. The protonema stage in liverworts is usually called a sporeling in other bryophytes (see below Form and function).
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