The spore on germination forms a short filament which soon broadens out into the thalloid protonema.
The protonema forms a flat, lobed, thalloid structure attached to the soil by rhizoids, and the plants arise from marginal cells.
In thalloid forms fimbriate or lobed margins or outgrowths from the surface lead to the same result.
One thalloid form has already been described in Pellia (fig. 2).