Definitions
American Heritage® Dictionary of the English Language, Fourth Edition
- n. The green filamentous growth that arises from spore germination in liverworts and mosses and eventually gives rise to a mature gametophyte.
Century Dictionary and Cyclopedia
- n. In Muscineæ, a pluricellular, confervoid or filamentous, usually chlorophyllose, structure upou which the leafy plant which bears the sexual organs arises as a lateral or terminal shoot. Also protoneme.
Wiktionary
- n. botany A filament of cells that forms following the germination of the spores of mosses and liverworts
GNU Webster's 1913
- n. (Bot.) The primary growth from the spore of a moss, usually consisting of branching confervoid filaments, on any part of which stem and leaf buds may be developed.
Etymologies
- proto- + Greek nēma, thread. (American Heritage® Dictionary of the English Language, Fourth Edition)
Examples
“The spores are set free by the bursting of their chamber, and each germinates, putting out a branched thread of cells called a protonema, which may perhaps properly be termed a third generation in the cycle of the plant; for it is only from buds developed on this protonema that the leafy sexual plant arises.”
“The protonema is not persistent, and the plants are well developed, resembling those of _Pleuridium_.”
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"
“The moss-plants arise from single projecting cells, and numerous plants may spring from the protonema developed from a single spore.”
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"
“The spore on germination forms a short filament which soon broadens out into the thalloid protonema.”
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"
“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.”
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"
“In addition to the leaves the stem often bears hair-like structures of different kinds, some of which correspond to modified branches of protonema.”
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"
“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.”
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"
“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.”
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"
“The protonema forms a flat, lobed, thalloid structure attached to the soil by rhizoids, and the plants arise from marginal cells.”
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"
“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.”
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"
Lists
These user-created lists contain the word ‘protonema’.
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Palynology
List of terms used in the study and classification of pollen and spores - both fossil and modern.
tetrad, abporal, ectoaperture, lacuna, grain, spore, lophate, acalymmate, monad, polyad, hexad, calymmate and 513 more...
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