Mosses: what are they, characteristics and examples

Mosses are bryophytic non-vascular plants . Non-vascular plants are those that do not have xylems or phloemes that allow them to distribute water and nutrients through their structure. However, although they lack these complex structures, some mosses do have more basic and simple vascular tissues, with which to internally transport the water they collect.

The bryophyte plants also are the most important group within the nonvascular plants . These are small plants, which tend to spread in the form of a tablecloth along surfaces that are sometimes quite extensive. They are chlorophyll plants, with which they can carry out photosynthesis and owe their generally green color to the chlorophyll pigments . Bryophyte plants are divided into liverworts, hornworts and mosses, which are the group that concerns us.

Learn more about Bryophyte Plants: examples and characteristics with this other AgroCorrn article.

These are the main characteristics of mosses :

• Mosses, as part of the group of non-vascular plants , are very primitive plants . They were the first plants to develop in the terrestrial environment together with ferns.
• They are very small plants, as they do not have organs that allow them to support large structures, and they have a high dependence on environmental humidity and water in the soil or medium to which they cling, since without the latter they cannot reproduce.
• They represent the evolutionary transition of plants from the totally aquatic environment to the terrestrial habitat and currently have around 11,000 species.
• They can thrive in a wide variety of habitats, with altitudes from sea level to almost 5,000 meters above sea level. Despite this, its favorite area is at altitudes between 1,900 and 3,800 meters above sea level, where high levels of humidity favor its development.
• They tend to form an important part of the biomass of the environments in which they are found, usually as upholstery or mattress, which is why they perform a very prominent function by retaining both water and nutrients , thus preventing rains or elements from cleaning the soil from them.
• Its reproduction is sexual, as we explain below.

Reproduction of mosses

Mosses have a sexual reproduction based on two alternate phases: haploid and diploid.

The part of the plant that we usually recognize as moss is the gametophyte, the haploid generation . The antheridium, which is the male sexual part of the plant, or the archegonium, which is the female sexual organ, develop in the gametophyte. When the antheridium breaks, it fertilizes the archegonium, which gives way to the diploid phase of the moss, in which a sporophyte develops. The sporophyte looks like a small capsule at the end of a stem that rises above the moss mantle, looking like a small flower.

This capsule contains the spores , which it will eventually release so that the water or the media can transport them to another place, where they will give rise to a protoneme, which will grow to form another gametophyte, thus returning to the predominantly haploid phase. Here we explain more about what spores are .

As mentioned above, mosses need plenty of moisture, so they tend to thrive in humid areas and in the shade . They cling to the surface with their rhizoids, which are small root-like structures whose only function is to support them. They form carpets on rocks, mud, wood or on the ground of large forest masses, being an important part of the understory .

They play a very important role in the colonization of terrestrial areas , since they are, together with lichens, the first to populate some areas and create organic matter that will later allow the development of more complex species.

Some mosses can stop their metabolism practically completely in dry conditions, to resume their activity for long periods of time later, as soon as they receive water again. They are also good indicators of air pollution , as some species are sensitive to it and serve as a marker.

The classification of mosses includes 8 classes : Bryopsida, Takakiopsida, Sphagnopsida, Polytrichopsida, Oedipodiopsida, Tetraphidopsida, Andreaeopsida and Andreaeobryopsida.

Within these classes, we find a large number of species or types of mosses , some of them quite generally known. The most common of these species is Bryopsida, which includes 95% of the mosses, thus being the most representative of this group of plants as well. Other mosses, such as those belonging to the Sphagnopsida class, commonly known as sphagnum, are easy to identify due to their particular appearance, reminiscent of small succulents. It is normal for their appearance to resemble them: they are capable of absorbing up to 20 times their weight in water.

These are some names of mosses :

• Weymouthia soft
• Eriopus remotifolius
• Dendroligotrichum dendroides
• Sphagnum magellanicum
• Hylocomium splendens
• Climacium dendroides
• archidium alternifolium
• Zygodon menziesii
• Dicranum scoparium
• Tortula muralis

If you want to read more articles similar to Mosses: what they are, characteristics and examples , we recommend that you enter our Biology category .