Liverworts and Mosses

Both liverworts and mosses are types of plants that grow in soil or on rocks and have stems, leaves, and roots. They have different forms of reproduction, and their cells hold mucilage, which is a sticky lipid that resists water loss from the plant. Liverworts are mostly found throughout the temperate world. There are more than 5,000 species of liverworts.

There are three principal groups of mosses; these include sphagnum mosses which they can be found through the world’s wet areas such as bogs and swamps; horn mosses which mainly grow in North America; and hair mosses which grow in alpine regions.

What are Liverworts?

Liverworts are non-vascular plants, which means that they do not have xylem or phloem tissues. Non-vascular plants are those that do not possess a woody stem or a system of conduits (xylem and phloem) for the transport of fluids (i.e., water and minerals) to leaves and other plant organs. They have a simple form of reproduction such as apomixis (asexual reproduction), fragmentation, and gemmae (vegetative buds). Liverworts also reproduce using spores that are produced in sporangia.

Liverworts are small plants, with some species attaining a height of just 1 to 3 centimetres.

Functions of Liverworts

Although only a few species of liverworts such as Marchantia polymorpha and Conocephalum canadense are polyploid (i.e., containing more than two paired sets of chromosomes), most liverworts are diploid (i.e., having two paired sets of chromosomes, one set from each parent). Many species of liverworts can conduct photosynthesis in bright light using an alternation of haploid and diploid generations, a process known as heteroecism. Asexual reproduction is the dominant form of reproduction found in liverworts.

There are about 90 species of liverworts, and a great part of them are endemic to various parts of the world.

Liverwort: Identification

Liverworts are small plants. The plants can take on either simple or compound leaf forms depending on the species, but some species have leaves that lack vascular tissue. Each leaf contains a peltate midrib, which may bear long hairs or scales. Most microsporangia (i.e., spores) are borne singly at the end of the stem or the base of the leaves. They rarely have true roots and they absorb water and nutrients directly through their leaves and stems via their cuticle (i.e., thin layer that covers all internal organs).

What are Mosses?

Mosses are small plants with leaves that are generally flattened and have some degree of photosynthetic capacity. The plants have stems, which may be upright, prostrate, or creeping on the ground. There are two main types of moss; these include true mosses and liverworts. True mosses are vascular plants that possess conducting tissue known as xylem and phloem, similar to other major groups of seed-bearing vascular land plants such as the ferns and gymnosperms.

Moss reproduction occurs both sexually and asexually; in general, a haploid phase is followed by a diploid phase. Mosses are usually found as single-celled gametophyte colonies.

Functions of Mosses

Mosses have tissues called rhizines (i.e., roots of the plant) that provide the means whereby mosses can establish themselves in moist, shady places. The leaves of mosses such as Psilotum, Selaginella, and Peat mosses are needle-like and have lobed margins. Mosses sometimes have rhizoids growing at the base of their leaves; they obtain nutrients from other organisms breaking down dead organic matter in the soil.

Mosses can grow either as single- or multi-cellular organisms. Although true mosses are relatively rare, they are considered to make up the majority of mosses that occur in moist habitats.

Moss: Identification

Mosses are small plants, with some species attaining a height of just 1 to 3 centimetres. They may have either simple or compound leaf forms depending on the species, but some species do not possess vascular tissue. Mosses may have simple stems arising from rhizoids that grow at the base of their leaves; they seldom have true roots and they absorb water and nutrients through their leaves and stems via their cuticle (i.e., thin layer that covers all internal organs).

Conclusion

After a thorough review of liverworts and mosses and their respective reproductive processes, it is concluded that they each have their unique features. However, it can be combined. For example, Liverworts can have both single-celled and multi-cellular reproductive patterns.