Protonema

noun

1. The filamentous growth that arises following spore germination in liverworts and mosses and develops into a mature gametophyte.
2. 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.
3. 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.
4. A filament of cells that forms following the germination of the spores of mosses and liverworts