Bryophytes are a group of plants characterized by the dominant photosynthetic gametophyte (almost always perennial), monosporangiated sporophytes, and a rather slight differentiation of conducting tissues. These three important characteristics separate them from the other main groups of plants: ferns, gymnosperms and flowering plants.

However, bryophytes constitute an artificial group because its members (mosses, liverworts & hornworts) don't share a common ancestor, representing three independent evolutionary lineages. The differences among these three plant groups lie on the general morphology of the gametophytes and in the structure of the sporophytes, mainly.

HORNWORTS

THALLOID LIVERWORTS

LEAFY LIVERWORTS

MOSSES

With the following key you would be able to differentiate between bryophyte groups (for the terminology use the online version of TROPICOS glossary):

1. Plants more or less flattened, thaloid, without stems or leaves........................2

1’. Plants not flattened, with evident stems and leaves.....................................3

2. Thalli crunchy when breaking, always in very humid places or next to the water; sporophytes born from a kind of horn made of gametophytic tissue, from which emerges a long, cylindric capsule, that opens by its distal extreme in two valves containing a central columella surrounded by spores, with pseudo-elaters (only Megaceros and Dendroceros have real elaters); seta lacking.......hornworts

2’. Thalli not crunchy when breaking, growing from very dry places to underwater; sporophytes emerging from a foliose perichaetium, sometimes very reduced; capsules globose on top of a hyaline seta or emerging from sporangiophores umbrella shaped, dehiscent by four longitudinal valves, with elaters, and without columella...... ..........................................................................liverworts (in part)

3. Plants with bilateral simmetry, generally postrated and sometimes with a row of ventral differentiated leaves (amphigastria); leaves without nerve, without alar cells, generally lobed or laciniated; sporophytes ephimeral, opening by four longitudinal apertures at maturity, without operculum, peristome, or columella; elaters present.................................................................liverworts (in part)

3’. Plants generally erect, with leaves arranged radially throughout stems (rarely flattened), without amphigastria (with a few exceptions); leaves generally with a nerve, sometimes with differentiated alar cells, never lobed; sporophytes persistent, formed by a capsule at the extreme of a seta, generally with operculum, columella and peristome; elaters absent...........................................................mosses

Juan Larraín 2009

Cite this page as:

Larraín, J. 2009. Musgos de Chile. URL: http://www.musgosdechile.cl (include the date when the information was obtained)