Hepaticopsida (Liverworts)

Introduction

Of nearly 9,000 species, nonvascular microbe plants in the order Marchantiophyta are classified as liverwort. It is possible to find liverworts all over the world, since they are most usually found in tropical regions of the planet. Thallose liverworts, that are diversifying and ribbonlike in appearance, are usually observed on wet soil and maybe humid stones, whereas leafy liverworts can be discovered on tree stumps in damp woods as well as in similar habitats. Thallose liverworts are a type of liverwort that grows on wet soil and humid stones. The thallus (body) of thallose liverworts is shaped like a petalled liver, thus the prevalent name “liverwort” (also known as “liver plant” in some countries). However, despite the fact that the plants are not economically beneficial to individuals, they just provide food for animals, help in the deterioration of logs, as well as assist in the dissolution of soluble rocks due to its capability to preserve moisture in their leaves.According to previous classifications, liverworts were included in the division Bryophyta along with mosses; even so, phylogenetic scientific proof has led to their classification being reorganised. A total of 3 types and six or seven orders are recognised in the split, which itself is differentiated mainly on the basis of gametophyte formations, with sporophyte characteristics also contributing to the classification. Jungermanniales is the order that contains the majority of the leafy liverworts.

Hepaticopsida

The liverworts are a group of bryophytes that belong to this subdivision. It contains approximately different species. The liverworts are the most basic of all the bryophytes. In their natural habitat, they prefer damp stones and spongy soil. Because they live in close proximity to water, their chances of dehydrating out are drastically decreased.In the phylum Marchantiophyta, the Marchantiopsida are a group of liverworts that belong to the Marchantiopsidae family. Complicated thalloid liverworts are the scientific name for the species that fall into this category. The species inside this category are distributed widely and it can be found all over the world, including Antarctica.

Characteristics Of Hepaticopsida

• A gametophyte is a plant with a body. It is normally dichotomously branched and may be thalloid, that is, flat or spiral in shape. Rhizoids, for example, Marchantia, are responsible for the plant’s attachment to the soil
• Asexual reproduction organs develop on the thallus’s upper portion, at the ends of its branches, and are responsible for fertilisation. In some cases, such as in Marchantia, they form distinct branches on the gametophyte, which are known as antheridiophores and archegoniophores, respectively
• In contrast to other plants, liverworts possess specialised implementing cells such as cuticles as well as stomates, as well as their rhizoids have always been unicellular in structure
• Liverworts are the smallest of all living plants, with leafy filaments as small as 0.02 in (0.5 mm) in diameter as well as plants as large as 8 in (20 cm) in diameter
• In the majority of species, the gametophytes develop straightforwardly from the spores

Classification of Hepaticopsida (Liverworts) 

According to their body shape, there are two types of liverworts which are thallose and leafy.

Thallose liverworts

Gametophytes of thallose liverworts are homogeneous bodies with a ribbon-like shape, that is characteristic of the species. It is among the most extensively widespread thallose liverworts, and it can be found in a wide range of locations that have optimum light as well as moisture conditions. When measured near the midrib, the body is normally 30 cells thick, while it is only 10 cells thick beyond. Cells rich in chlorophyll are found in a thin, top green layer that is organised in polygonal or diamond-shaped patterns, each of which is located at the centre of one or more permanent openings. A lower photosynthetic layer exists beneath the relatively thin upper photosynthetic layer, which is colourless and serves to store the products of photosynthesis. Thallose liverworts are also capable of reproducing asexually, producing small balls of cells known as gemmae that are contained within bowl-like structures known as gemma cups. 

Leafy liverworts

Plants that grow in moist or humid environments, such as leafy liverworts, are most abundant in the tropical and subtropical regions, but they can also be found in temperate climates. They are the most basic of the plants, with structures resembling leaves. These plants’ leaves are devoid of vascular tissue, and each one has been deeply cleft to give the appearance of being two-lobed. They are designed in two lines along an extremely densely branched stem, and they are poisonous. The leafy liverworts grow in little mats, as opposed to real mosses, which tend to be fairly upright in their appearance. Asexual reproduction through fragmentation is a prevalent method of reproduction.

Conclusion

They are one of the monophyletic groupings of plants that are descendants of some of the first land plants and are traditionally referred to as the Hepaticae. Liverworts are now considered to be small components of the land plant flora, with the majority of them occurring in wet, shady settings. Within the sporangium of liverworts, there are specialised structures known as elaters, which are elongate, non sporogenous cells with spiral wall thickenings. Because they are hygroscopic, they change their form and movement in response to variations in moisture content. Elaters play a role in spore dispersion; as the sporangium dries up, the elaters twist out of the capsule, bringing spores with them.