NON-VASCULAR PLANTS: CHARACTERISTICS, TYPES AND SPECIES - BIOLOGY - 2025

The nonvascular plants are those that lack roots, true stems, leaf veins and vessels tubular conductive liquid vascular plants. These types of plants do not have a vascular system, that is, they do not have xylem or phloem. Despite not having these tissues, they have other simpler structures for transporting water.

The plant kingdom includes two major divisions: vascular plants and non-vascular plants. The latter do not have a great variety of types of specialized fabrics. Liverwort leaves, for example, have no cuticle, stomata, internal air spaces, and no xylem or phloem. This does not allow them to control the loss of water and they are called poikilohydric.

Moss, a non-vascular plant

Non-vascular plants include only mosses (Phylum Bryophyta, 10,000 species worldwide), liverworts (Phylum Hepatophyta, 6,000 species), and hornworts (Phylum Anthocerophyta).

For this reason, it is one of the botanical groups whose research is usually complicated to carry out, hence the information that exists on each of the species is not as complete as it is with other types of plants.

These plants are generally small and live in varied environments. They can be found in jungles, deserts, at sea level or even at very high altitudes.

Most of these plants absorb water through the surface of their tissues, which is why they are located in humid places or under water because those environments facilitate the absorption process.

Non-vascular plant types

Mosses (Phylum Bryophyta)

They have very primitive vessels and do not form either xylem or phloem. They are anchored to the ground through the rhizoids. Instead of a stem, they have something similar called cauloid and instead of leaves, they have very similar blades called phylloids.

In upland habitats, mosses easily colonize in sun or shade, rocky crevices. They are important to prevent erosion, retain water, and accelerate soil formation. This facilitates the colonization of these sites by other plants.

Familiar moss plants are haploid individuals (gametophytes) that produce sperm and / or eggs in separate structures between the upper leaves of the moss.

Rainwater or heavy dew is necessary to transport the sperm to the egg for sexual reproduction.

Fertilization of the ovum by sperm results in a diploid zygote that grows into a sporophyte that has a spore capsule in its upper part in which meiosis (spore formation) occurs.

The filament and capsule of the diploid sporophyte remain attached to the haploid gametophyte. The spores are released from the capsule and germinate to form new haploid individuals.

Hepatic (Phylum Hepatophyta)

These types of non-vascular plants have nothing like vessels, they don't even show distinguishable structures unlike mosses. They absorb water and nutrients through their entire surface.

They can measure from 0.05 to 20 cm in diameter. Liverworts are included in the Hepatophyta, a division that includes about 8,500 different species that grow around the world, in places like the Arctic and the tropics. There are approximately 60 different families of liver plants.

It commonly grows in humid places although some can grow in sandy and dry areas. They can grow in two ways: having a shape similar to a leaf or talose, growing in large flat sheets. Its leaves can be mistaken for mosses.

Horn Hepatic (Phylum Anthocerophyta)

Horn liverworts are a type of Bryophyte. Its name is due to its long sporaphytes that are horn-shaped, in this structure the plant produces spores. They can measure between 1.27 and 1.9 cm.

These plants grow in temperate and tropical regions around the world. They can be found on tree trunks, along riverbanks, or in wet places.

Because they have hair-like anchoring structures, they can adhere to logs or the ground.

Representative species of non-vascular plants

Among liverworts, 4 to 10 species are recognized, although information on most of them is difficult to find, and is reduced to botanical encyclopedias, or to specialists who are knowledgeable on the subject.

In any case, it is known that most owe their name to the geographical location where they are present, among them are:

H. nobilis var hepatic

They are found from the north of the Alps to Scandinavia.

H. nobilis var Pyrenean

Originally from the Pyrenees.

H. nobilis var japonica

They can be found in Japan.

H. nobilis var. Pubescens

They are located in Japan.

H. transsilvanica

They are generally found in the Carpathians and Transylvania.

H. acutiloba

They are commonly seen in North America.

H. americana

Native to North America.

H. polymorpha merchant

It forms dense lawns of thalli that reach 10 cm in length. It usually grows in bogs or wet meadows, in general, it grows in highly humid areas.

Lunularia cruciata

Its name, in Latin, refers to the cups in the shape of the moon. It is commonly found in Europe, California, and Australia.

In it you can get lunularic acid, a dihydrostilbenoid.

Riccia fluitans

It can measure between 1 and 2 cm wide and 1 and 5 cm high. It is capable of forming a large vegetable sphere. It is considered by many as a plague.

Polytrichum commune

It is a moss whose common lengths are 5 to 10 cm. It is found throughout temperate and boreal latitudes in the Northern Hemisphere and also in Mexico, some Pacific islands, and Australia.

It generally grows in damp swamps and flower streams.

Vesicularia dubyana

Also known as Java moss, it is a freshwater plant. It commonly lives in countries in South Asia, including the island of Java, from which it owes its name.

It is generally seen in freshwater aquariums.

References

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