When you see text which is bold and italic, clicking on that text will take you to the relevant term in the Glossary
Before you start:
Throughout this web site you will see terminology that you may, or may not have seen before. This terminology is clarified by bold italic links within the main text to the Glossary where each term is explained.
There is also a section explaining the basics of Taxonomic classification.
Bryophytes have both Taxonomic and common or colloquial names.
Common names are those attributed historically to a species.
Taxonomic names are more precise and in practice always used. Taxonomic names are binomial in that each species is given a name that consists of two parts.
The first part is the Genus to which the species belongs and the second part is the name of the specific species.
For example, Polytrichum (Genus) juniperinum (species) Juniper Haircap (Common name)
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What are Bryophytes?
Everybody has at some time walked past, sat or stood on or near a Bryophyte (or Moss as we commonly call them). They grow on most surfaces in rural, urban, mountainous and coastal areas.
There are 1000 plus species found in the UK and most fairly are common. Some are extremely rare and a few species almost extinct. Others are so common that they cover large areas and grow on stone walls for miles. Where there is a wall, lawn, tree, roof, rockery, paved area there is almost always a Bryophyte nearby.
Commonly referred to as Bryophytes, this term is derived from the latin Bryophyta which was was once a single Division in the Kingdom of Plants (plantae)
That Division has since been divided into into three separate Divisions:
Bryophyta = Mosses
Marchantiophyta = Liverworts (also referred to as Hepatophyta)
Anthocerotophyta = Hornworts
Commonly, the three divisions are collectively referred to as Bryophytes. Where you see this term, remember it refers to all three Divisions.
Bryophytes have been on Earth for much longer than we have and although primitive they are extremely successful plants.
The are also extremely beautiful when examined closely and unlike anything else in the Plant world.
Reproduction in Bryophytes involves the production of spores or Vegetative propagules or Gemmae or a combination of all three and their distribution into the environment. This is detailed in the Biology section.
Two major factors determine how successful any species or genus of moss might be. The first one is the availability of water and the second a suitable environment (which includes the substrate ) in which the plant lives.
Air quality also can influence where some species can or cannot thrive.
Water
Mosses (all three divisions) are described as non-vascular plants and lack the circulatory systems found in vascular plants and trees where water and nutrients are absorbed by roots then circulated around the plant body in vessels.
Although Bryophytes do not have this ability and are thus described as non-vascular plants, they do have conductive tissues to help with the ingestion of water and nutrients. This is dealt with in the Biology section.
As you can see from the attached image, a spore from this species has found a shaded and very moist location at the base of a high stone wall in a fairly isolated area of old woodland to start a colony.
It has the substrate it needs and isn't normally exposed to bright sunlight or very high winds which might affect it.
In amongst the stems and leaves of this large area of moss will be a fairly large number very small and very busy invertebrates, all enjoying a reasonably warm and humid environment.
Bryophytes do not produce flowers and seeds like vascularplants, so there is no pollen or nectar created. Their leaves can resemble flower heads, as with the image to the left. Their reproductive process revolves around the production and distribution of spores in large numbers and this is one of the reasons they are so successful in increasing their numbers in the right circumstances.
You would imagine that a plant relying entirely upon plenty of moisture to survive and reproduce would be prone to dying away completely in times of drought and prolonged periods of high temperatures.
Another feature of bryophytes is their innate ability to go for long periods without moisture to the stage of being completely desiccated and shrivelled up. Unlike flowers that do die from lack of water, mosses can recover completely from drying by taking in new moisture. This results in them looking nothing like the majority of pictures of lush green plants you may see in books when they are dry.
Re-hydration with a Bryophyte can be spectacular to watch as the plant is animated by the new moisture, changing shape and expanding to become whole again. The green colouration of bryophytes can take longer to re-appear after dry periods.