A protonema (plural: protonemata) is a thread-like chain of cells that forms the earliest stage (the haploid phase) of a bryophyte life cycle. When a moss or liverwort first grows from the spore, it grows as protonemata until it has grown enough to develop into a mature plant. Haploid (meaning simple in Greek) cells have only one copy of each chromosome. ... Bryophytes are embryophyte plants (land plants) that are nevertheless non-vascular: they have tissues and enclosed reproductive systems, but they lack vascular tissue that circulates liquids. ... Subclasses Andreaeidae Sphagnidae Tetraphidae Polytrichidae Buxbaumiidae Bryidae Archidiidae Moss on a rock Mosses are a type of simple or non-vascular plant. ... Orders Need to be entered Liverworts are non-vascular plants in the Class Marchantiopsida, formerly known as the Hepaticae. ... The term spore have several different meanings in biology. ...
The generation change discribed here is valid for all mosses, but the concrete shaping of gametophyte, sporophyte and protonema may be rather different in the several taxanomic divisions.
The protonema may be rather different in different moss-species.
The protonema develops cusps (B), from wich the gemetophytes (C) arise.
The induction of shoot buds from the filamentous protonema of
Dark-grown protonemata on filter papers were placed onto one of the two types of hormone-supplemented media; after various amounts of time, filters with the protonema were removed, washed with three 25-mL aliquots of liquid basal medium to reduce hormone carryover, and placed onto the other type of hormone-supplemented medium.
Shaw, A. 1991 The genetic structure of sporophytic and gametophytic populations of the moss, Funaria hygrometrica.
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