Difference Between Liverworts and Mosses

Main Difference – Liverworts vs Mosses

Liverworts, mosses, and hornworts are the three representative groups of plants in the phylum Bryophyta. Since bryophytes live in shady, wet environments, they are considered as amphibians of the plant kingdom. Both liverworts and mosses do not have a circulatory system like higher plants. They asexually reproduce by producing spores. The sexual reproduction only occurs in a wet environment; hence, both liverworts and mosses show alternation of generations. Liverworts and mosses differ in the morphology of the haploid gametophyte. The gametophyte is the prominent stage of the life cycle of bryophytes. The main difference between liverworts and mosses is that the gametophyte of liverworts is a thallose or a foliose whereas the gametophyte of mosses is a prostrate, branched filamentous structure.

Key Areas Covered

1. What are Liverworts
      – Definition, Characteristics, Examples
2. What are Mosses
      – Definition, Characteristics, Examples
3. What are the Similarities Between Liverworts and Mosses
      – Outline of Common Features
4. What is the Difference Between Liverworts and Mosses
      – Comparison of Key Differences

What are Liverworts

Liverworts are non-vascular plants with a prominent gametophyte, which consist of either leaf-like stems or lobes. They are classified as the division Marchantiophyta under the phylum Bryophyta. The gametophyte is the prominent generation of liverworts. The leafy liverworts consist of a single cell layer in their leaves. But, thallose liverworts consist of several cell layers.

Difference Between Liverworts and Mosses

Figure 1: Liverwort

Liverworts grow by sprawling across the soil, rocks, and other plants. The root-like rhizoids are involved in attaching the plant to the substrate and absorbing water. The leaf-like structures are arranged in two or three rows in a flattened pattern. The less prominent sporophyte generation develops from the fertilization of gametes and it produces the sporangium at the apex. The most common examples of liverworts are Riccia, Marchantia, and Porella.

What are Mosses

Mosses are a type of non-vascular plants that consist of a prominent gametophyte with leafy stems. They are classified under the phylum Bryophyta as the division Bryophyta. The mosses are characterized by leafy stems. But, these leaves or stems are not true. The root-like structures or the rhizoids are multicellular ion mosses. The sporophyte is attached to the female gametophyte and consist of a seta and a capsule. The capsule is covered by the operculum. Once the operculum falls off in a ripen capsule, the teeth of the capsule opening become visible. The seta holds the sporangium to the wind.

Figure 2: Moss with Sporangia

Mosses are the largest division of the phylum Bryophyta. The most common examples of mosses are Funaria, Polytrichum, and Sphagnum.

Similarities Between Liverworts and Mosses

Liverworts and mosses are plants that live in terrestrial, wet environments.
Both liverworts and mosses are small plants with morphologically different sporophytes and gametophytes.
The gametophyte is dominant over the sporophyte in both liverworts and mosses.
Both liverworts and mosses contain superficial gametangia.
The sporophyte is partly depended on the gametophyte.
Both liverworts and mosses consist of many chloroplasts per cell.
Both liverworts and mosses are non-vascular plants.
Both liverworts and mosses are non-flowering plants.
Both liverworts and mosses lack true stems, roots or leaves.
The thin, hair-like rhizoids attach the plant to the substrate.
The stem-like structures are called caulalia and the leaf-like structures are called phyllids.
The cuticles and stomata are absent in both liverworts and mosses.
The fertilization of both liverworts and mosses depend on water.

Definition

Liverworts: Liverworts are non-vascular plants consisting of leaf-like lobes or stems.

Mosses: Mosses are non-vascular plants consisting of leafy stems.

Division

Liverworts: Liverworts belong to the division Marchantiophyta.

Mosses: Mosses belong to the division Bryophyta.

Morphology of the Gametophyte

Liverworts: The gametophyte of liverworts is a thallose or foliose.

Mosses: The gametophyte of mosses is a foliose.

Symmetry

Liverworts: The liverworts are dorsiventral or radial.

Mosses: The mosses are radial.

Rhizoids

Liverworts: The rhizoids of liverworts are unicellular.

Mosses: The rhizoids of mosses are pluricellular.

Protonemata

Liverworts: The protonemata are reduced in liverworts.

Mosses: Mosses produce prominent protonemata.

Leaf Arrangement

Liverworts: The leaf-like structures are arranged in two or three rows in a flattened pattern.

Mosses: The leaf-like structures are arranged in a spiral or whorl.

Examples

Liverworts: Riccia, Marchantia, and Porella are examples of liverworts.

Mosses: Funaria, Polytrichum, and Sphagnum are examples of mosses.

Conclusion

Liverworts and mosses are two classifications of the phylum Bryophyta. The phylum Bryophyta consist of the most primitive plants in the kingdom Plantae. They are non-vascular plants with a prominent gametophyte. The gametophyte is not differentiated into root, stem or leaves. Liverworts are thallose or foliose plants whereas mosses are foliose plants. The main difference between liverworts and mosses is the morphology of the gametophyte in each plant.

Reference:

1.“Liverwort.” Encyclopædia Britannica, Encyclopædia Britannica, inc., Available here. Accessed 22 Aug. 2017. 2. Biologi, Belajar. “20 Characteristics of Moss Plant, Examples, Benefits, Classification & metagenesis.” Belajar Biologi, Available here. Accessed 22 Aug. 2017.

Image Courtesy:

1. “A liverwort – Conocephalum conicum – geograph.org.uk – 930674” By Lairich Rig (CC BY-SA 2.0) via Commons Wikimedia
2. “Moss spores” By Lordgrunt – Own work (CC BY 3.0) via Commons Wikimedia