Haplomitriopsida Stotler & Stotl.-Crand.

Jungermanniopsida Stotler & Stotl.-Crand.

Marchantiopsida Stotler & Stotl.-Crand.

The Marchantiophyta [mɑː(r)ˌkæntiˈɑːfɪtə] (help·info) are a division of bryophyte Bryophytes are all embryophytes that are non-vascular: they have tissues and enclosed reproductive systems, but they lack vascular tissue that circulates liquids. They neither have flowers nor produce seeds, reproducing via spores. The term bryophyte comes from Greek βρύον - bryon, "tree-moss, oyster-green" + φυτόν - fyton & plants Plants are living organisms belonging to the kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae. About 350,000 species of plants, defined as seed plants, bryophytes, ferns and fern allies, are estimated to exist currently. As of 2004, some 287,655 species had been commonly referred to as hepatics or liverworts. Like other bryophytes, they have a gametophyte The gametophyte produces male or female gametes , by a process of cell division called mitosis. The fusion of male and female gametes produces a diploid zygote, which develops by repeated mitotic cell divisions into a multicellular sporophyte. Because the sporophyte is the product of the fusion of two haploid gametes, its cells are diploid,-dominant life cycle, in which cells of the plant carry only a single set of genetic information.

It is estimated that there are 6000 to 8000 species of liverworts, though when Neotropical regions are better studied this number may approach 10,000. Some of the more familiar species grow as a flattened leafless thallus Thallus, from Latinized Greek θαλλός , meaning a green shoot or twig, is an undifferentiated vegetative tissue of some non-mobile organisms, which were previously known as the thallophytes, but most species are leafy with a form very much like a flattened moss Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems. At certain times mosses produce spore capsules which may appear as beak-like. Leafy species can be distinguished from the apparently similar mosses on the basis of a number of features, including their single-celled rhizoids In fungi, rhizoids are small branching hyphae that grow downwards from the stolons that anchor the fungus. They release digestive enzymes and absorb digested organic material. In land plants, rhizoids are trichomes that anchor the plant to the ground. In the liverworts, they are absent or unicellular, but multicelled in mosses. In vascular plants. Leafy liverworts also differ from most (but not all) mosses in that their leaves never have a costa (present in many mosses) and may bear marginal cilia (very rare in mosses). Other differences are not universal for all mosses and liverworts, but the occurrence of leaves arranged in three ranks, the presence of deep lobes or segmented leaves, or a lack of clearly differentiated stem and leaves all point to the plant being a liverwort.

Liverworts are typically small, usually from 2-20 mm wide with individual plants less than 10 cm long, and are therefore often overlooked. However, certain species may cover large patches of ground, rocks, trees or any other reasonably firm substrate on which they occur. They are distributed globally in almost every available habitat, most often in humid locations although there are desert and arctic species as well. Some species can be a nuisance in shady green-houses or a weed in gardens.[4]

Contents

Physical characteristics

Description

Most liverworts are small, usually from 2–20 millimetres (0.08–0.8 in) wide with individual plants less than 10 centimetres (4 in) long,[5] so they are often overlooked. The most familiar liverworts consist of a prostrate, flattened, ribbon-like or branching structure called a thallus Thallus, from Latinized Greek θαλλός , meaning a green shoot or twig, is an undifferentiated vegetative tissue of some non-mobile organisms, which were previously known as the thallophytes (plant body); these liverworts are termed thallose liverworts. However, most liverworts produce flattened stems with overlapping scales or leaves in three or more ranks, the middle rank being conspicuously different from the outer ranks; these are called leafy liverworts or scale liverworts.[6][7] (See the gallery below for examples.)

A thallose liverwort, Lunularia cruciata

Liverworts can most reliably be distinguished from the apparently similar mosses Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems. At certain times mosses produce spore capsules which may appear as beak-like by their single-celled rhizoids In fungi, rhizoids are small branching hyphae that grow downwards from the stolons that anchor the fungus. They release digestive enzymes and absorb digested organic material. In land plants, rhizoids are trichomes that anchor the plant to the ground. In the liverworts, they are absent or unicellular, but multicelled in mosses. In vascular plants.[8] Other differences are not universal for all mosses and all liverworts;[7] but the lack of clearly differentiated stem and leaves in thallose species, or in leafy species the presence of deeply lobed or segmented leaves and the presence of leaves arranged in three ranks, all point to the plant being a liverwort.[9][10] In addition, 90% of liverworts contain oil bodies in at least some of their cells, and these cellular structures are absent from most other bryophytes and from all vascular plants.[11] The overall physical similarity of some mosses and leafy liverworts means that confirmation of the identification of some groups can be performed with certainty only with the aid of microscopy Microscopy is the technical field of using microscopes to view samples or objects. There are three well-known branches of microscopy, optical, electron and scanning probe microscopy or an experienced bryologist.

Liverworts have a gametophyte The gametophyte produces male or female gametes , by a process of cell division called mitosis. The fusion of male and female gametes produces a diploid zygote, which develops by repeated mitotic cell divisions into a multicellular sporophyte. Because the sporophyte is the product of the fusion of two haploid gametes, its cells are diploid,-dominant life cycle, with the sporophyte All land plants, and some algae, have life cycles in which a haploid gametophyte generation alternates with a diploid sporophyte, the generation of a plant or alga that has a double set of chromosomes. A multicellular sporophyte generation or phase is present in the life cycle of all land plants and in some green algae. For common flowering plants dependent on the gametophyte.[11] Cells in a typical liverwort plant each contain only a single set of genetic information, so the plant's cells are haploid Ploidy is the number of complete sets of chromosomes in a biological cell. In humans, the somatic cells that compose the body are diploid , but sex cells (sperm and egg) are haploid. In contrast, tetraploidy (four sets of chromosomes) is a type of polyploidy and is common in plants, and not uncommon in amphibians, reptiles, and various species of for the majority of its life cycle. This contrasts sharply with the pattern exhibited by nearly all animals and by most other plants. In the more familiar seed plants The spermatophytes (also known as phanerogams) comprise those plants that produce seeds. They are a subset of the embryophytes or land plants. The living spermatophytes form five groups:, the haploid generation is represented only by the tiny pollen Pollen is a fine to coarse powder consisting of microgametophytes , which produce the male gametes (sperm cells) of seed plants. A hard coat covering the pollen grain protects the sperm cells during the process of their movement between the stamens of the flower to the pistil of the next flower and the ovule Ovule literally means "small egg." In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integuments forming its outer layer, the nucellus , and the megaspore-derived female gametophyte (or megagametophyte) in its center. The megagametophyte (also called, while the diploid Ploidy is the number of complete sets of chromosomes in a biological cell. In humans, the somatic cells that compose the body are diploid , but sex cells (sperm and egg) are haploid. In contrast, tetraploidy (four sets of chromosomes) is a type of polyploidy and is common in plants, and not uncommon in amphibians, reptiles, and various species of generation is the familiar tree or other plant.[12] Another unusual feature of the liverwort life cycle is that sporophytes (i.e. the diploid Ploidy is the number of complete sets of chromosomes in a biological cell. In humans, the somatic cells that compose the body are diploid , but sex cells (sperm and egg) are haploid. In contrast, tetraploidy (four sets of chromosomes) is a type of polyploidy and is common in plants, and not uncommon in amphibians, reptiles, and various species of body) are very short-lived, withering away not long after releasing spores.[13] Even in other bryophytes Bryophytes are all embryophytes that are non-vascular: they have tissues and enclosed reproductive systems, but they lack vascular tissue that circulates liquids. They neither have flowers nor produce seeds, reproducing via spores. The term bryophyte comes from Greek βρύον - bryon, "tree-moss, oyster-green" + φυτόν - fyton &, the sporophyte is persistent and disperses spores over an extended period.

Life cycle

Life cycle of a typical liverwort

The life of a liverwort starts from the germination of a haploid spore In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoans. A chief difference between spores and seeds as dispersal units is that spores have very little stored to produce a protonema A protonema is a thread-like chain of cells that forms the earliest stage (the haploid phase) of a bryophyte life cycle. When a moss or liverwort first grows from the spore, it grows as a protonema which develops into a leafy gametophore, which is either a mass of thread-like filaments or else a flattened thallus.[14][15] The protonema is a transitory stage in the life of a liverwort, from which will grow the mature gametophore ("gamete A gamete is a cell that fuses with another gamete during fertilization (conception) in organisms that reproduce sexually. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete — called an ovum (or egg) — and-bearer") plant that produces the sex organs. The male organs are known as antheridia An antheridium is a haploid structure or organ producing and containing male gametes (called antherozoids or sperm). It is present in the gametophyte phase of lower plants like mosses and ferns, and also in the primitive vascular psilotophytes. Many algae and some fungi, for example ascomycetes and water moulds, also have antheridia during their (singular: antheridium) and produce the sperm cells. Clusters of antheridia are enclosed by a protective layer of cells called the perigonium (plural: perigonia). As in other land plants, the female organs are known as archegonia An archegonium , from the ancient Greek ἀρχή ("beginning") and γόνος ("offspring"), is a multicellular structure or organ of the gametophyte phase of certain plants producing and containing the ovum or female gamete. The archegonium has a long neck and a swollen base. Archegonia are typically located on the surface of (singular: archegonium) and are protected by the thin surrounding perichaetum (plural: perichaeta).[7] Each archegonium has a slender hollow tube, the "neck", down which the sperm swim to reach the egg cell.

Liverwort species may be either dioicous Bryophytes are all embryophytes that are non-vascular: they have tissues and enclosed reproductive systems, but they lack vascular tissue that circulates liquids. They neither have flowers nor produce seeds, reproducing via spores. The term bryophyte comes from Greek βρύον - bryon, "tree-moss, oyster-green" + φυτόν - fyton & or monoicous Bryophytes are all embryophytes that are non-vascular: they have tissues and enclosed reproductive systems, but they lack vascular tissue that circulates liquids. They neither have flowers nor produce seeds, reproducing via spores. The term bryophyte comes from Greek βρύον - bryon, "tree-moss, oyster-green" + φυτόν - fyton &. In dioicious liverworts, female and male sex organs are borne on different and separate gametophyte plants. In monoicious liverworts, the two kinds of reproductive structures are borne on different branches of the same plant.[16] In either case, the sperm must swim from the antheridia where they are produced to the archegonium where the eggs are held. The sperm of liverworts is biflagellate, i.e. they have two tail-like flagellae A flagellum is a tail-like structure that projects from the cell body of certain prokaryotic and eukaryotic cells, and functions in locomotion. There are some notable differences between prokaryotic and eukaryotic flagella, such as protein composition, structure, and mechanism of propulsion. An example of a flagellated bacterium is the ulcer- that aid in propulsion.[17] Their journey is further assisted either by the splashing of raindrops or the presence of a thin layer of water covering the plants. Without water, the journey from antheridium to archegonium cannot occur.

In the presence of such water, sperm from the antheridia swim to the archegonia and fertilisation Fertilisation , is the fusion of gametes to produce a new organism. In animals, the process involves a sperm fusing with an ovum, which eventually leads to the development of an embryo. Depending on the animal species, the process can occur within the body of the female in internal fertilisation, or outside in the case of external fertilisation occurs, leading to the production of a diploid sporophyte. After fertilisation, the immature sporophyte All land plants, and some algae, have life cycles in which a haploid gametophyte generation alternates with a diploid sporophyte, the generation of a plant or alga that has a double set of chromosomes. A multicellular sporophyte generation or phase is present in the life cycle of all land plants and in some green algae. For common flowering plants within the archegonium develops three distinct regions: (1) a foot, which both anchors the sporophyte in place and receives nutrients from its "mother" plant, (2) a spherical or ellipsoidal capsule, inside which the spores will be produced for dispersing to new locations, and (3) a seta (stalk) which lies between the other two regions and connects them.[17] When the sporophyte has developed all three regions, the seta elongates, pushing its way out of the archegonium and rupturing it. While the foot remains anchored within the parent plant, the capsule is forced out by the seta and is extended away from the plant and into the air. Within the capsule, cells divide to produce both elater An elater is a cell that is hygroscopic, and therefore will change shape in response to changes in moisture in the environment. Elaters come in a variety of forms, but are always associated with plant spores. In plants that do not have seeds, they function in dispersing the spores to a new location cells and spore-producing cells. The elaters are spring-like, and will push open the wall of the capsule to scatter themselves when the capsule bursts. The spore-producing cells will undergo meiosis In biology, meiosis is a process of reductional division in which the number of chromosomes per cell is halved. In animals, meiosis always results in the formation of gametes, while in other organisms it can give rise to spores. As with mitosis, before meiosis begins, the DNA in the original cell is replicated during S-phase of the cell cycle. Two to form haploid spores In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoans. A chief difference between spores and seeds as dispersal units is that spores have very little stored to disperse, upon which point the life cycle can start again.

Ecology

Today, liverworts can be found in many ecosystems across the planet except the sea and excessively dry environments, or those exposed to high levels of direct solar radiation.[18] As with most groups of living plants, they are most common (both in numbers and species) in moist tropical areas.[19] Liverworts are more commonly found in moderate to deep shade, though desert species may tolerate direct sunlight and periods of total desiccation.

Classification

Relationship to other plants

Traditionally, the liverworts were grouped together with other bryophytes Bryophytes are all embryophytes that are non-vascular: they have tissues and enclosed reproductive systems, but they lack vascular tissue that circulates liquids. They neither have flowers nor produce seeds, reproducing via spores. The term bryophyte comes from Greek βρύον - bryon, "tree-moss, oyster-green" + φυτόν - fyton & (mosses Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems. At certain times mosses produce spore capsules which may appear as beak-like and hornworts Hornworts are a group of bryophytes, or non-vascular plants, comprising the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. The flattened, green plant body of a hornwort is the gametophyte plant) in the Division Bryophyta, within which the liverworts made up the class Hepaticae (also called Marchantiopsida).[20][7] However, since this grouping makes the Bryophyta paraphyletic In phylogenetics, a group of organisms is said to be paraphyletic if the group contains its most recent common ancestor but does not contain all the descendants of that ancestor, the liverworts are now usually given their own division.[21] The use of the division name Bryophyta sensu latu is still found in the literature, but more frequently the Bryophyta now is used in a restricted sense to include only the mosses.

Two hypotheses on the phylogeny In biology, phylogenetics is the study of evolutionary relatedness among various groups of organisms , which is discovered through molecular sequencing data and morphological data matrices. The term phylogenetics is of Greek origin from the terms phyle/phylon (φυλή/φῦλον), meaning "tribe, race," and genetikos (γενετικός of land plants (embryophyta).

Another reason that liverworts are now classified separately is that they appear to have diverged from all other embryophyte The embryophytes are the most familiar group of plants. They include trees, flowers, ferns, mosses, and various other green land plants. All are complex multicellular eukaryotes with specialized reproductive organs. With very few exceptions, embryophytes obtain their energy through photosynthesis ; and they synthesize their food from carbon plants near the beginning of their evolution In biology, evolution is the change in the genetic material of a population of organisms from one generation to the next. Though the changes produced in any one generation are small, differences accumulate with each generation and can, over time, cause substantial changes in the organisms. This process can culminate in the emergence of new species. The strongest line of supporting evidence is that liverworts are the only living group of land plants that do not have stomata In botany, a stoma is a pore, found in the leaf and stem epidermis that is used for gas exchange. The pore is formed by a pair of specialized parenchyma cells known as guard cells which are responsible for regulating the size of the opening. Air containing carbon dioxide enters the plant through these openings where it is used in photosynthesis on the sporophyte All land plants, and some algae, have life cycles in which a haploid gametophyte generation alternates with a diploid sporophyte, the generation of a plant or alga that has a double set of chromosomes. A multicellular sporophyte generation or phase is present in the life cycle of all land plants and in some green algae. For common flowering plants generation.[22] Among the earliest fossils Fossils are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record. The study of fossils across geological time, how believed to be liverworts are compression fossils A compression fossil is a fossil preserved in sedimentary rock that has undergone physical compression. While it is uncommon to find animals preserved as good compression fossils, it is very common to find plants preserved this way. The reason for this is that physical compression of the rock often leads to distortion of the fossil of Pallaviciniites from the Upper Devonian The Devonian is a geologic period and system of the Paleozoic era spanning from 416 to 359.2 million years ago . It is named after Devon, England, where rocks from this period were first studied of New York The State of New York ( /nuːˈjɔrk/ ) is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts and Vermont to the east. The state has a maritime border with Rhode Island east of Long.[23] These fossils resemble modern species in the Metzgeriales.[24] Another Devonian fossil called Protosalvinia also looks like a liverwort, but its relationship to other plants is still uncertain, so it may not belong to the Marchantiophyta. In 2007, the oldest fossils assignable to the liverworts were announced, Metzgeriothallus sharonae from the Givetian (Middle Devonian The Devonian is a geologic period and system of the Paleozoic era spanning from 416 to 359.2 million years ago . It is named after Devon, England, where rocks from this period were first studied) of New York The State of New York ( /nuːˈjɔrk/ ) is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts and Vermont to the east. The state has a maritime border with Rhode Island east of Long, USA The United States of America is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its 48 contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south.[1]

Internal classification

Bryologists classify liverworts in the division Marchantiophyta. This divisional name is based on the name of the most universally recognized liverwort genus Marchantia.[25] In addition to this taxon A taxon is a group of (one or more) organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement. Defining what belongs or does not belong to such a taxonomic group is done by a taxonomist. It is not uncommon for one taxonomist to disagree with another on what exactly belongs to-based name, the liverworts are often called Hepaticophyta. This name is derived from their common Latin name as Latin was the language in which botanists published their descriptions of species. This name has led to some confusion, partly because it appears to be a taxon-based name derived from the genus The term comes from Latin genus "descent, family, type, gender" , cognate with Greek: γένος - genos, "race, stock, kin" Hepatica which is actually a flowering plant of the buttercup family Ranunculaceae. In addition, the name Hepaticophyta is frequently misspelled in textbooks as Hepatophyta, which only adds to the confusion.

The Marchantiophyta is subdivided into three classes:[26][27][28][29]

It is estimated that there are 6000 to 8000 species of liverworts, at least 85% of which belong to the leafy group.[3]

Economic importance

In ancient times, it was believed that liverworts cured diseases of the liver, hence the name.[31] In Old English, the word liverwort literally means liver plant.[32] This probably stemmed from the superficial appearance of some thalloid liverworts (which resemble a liver in outline), and led to the common name of the group as hepatics, from the Latin word hēpaticus for "belonging to the liver". An unrelated flowering plant, Hepatica, is sometimes also referred to as liverwort because it was once also used in treating diseases of the liver. This archaic relationship of plant form to function was based in the "Doctrine of Signatures".[33]

Liverworts have little direct economic importance today. Their greatest impact is indirect, through the reduction of erosion along streambanks, their collection and retention of water in tropical forests, and the formation of soil crusts in deserts and polar regions. However, a few species are used by humans directly. A few species, such as Riccia fluitans, are aquatic thallose liverworts sold for use in aquaria. Their thin, slender branches float on the water's surface and provide habitat for both small invertebrates and the fish that feed on them.

Gallery

A small collection of images showing liverwort structure and diversity:

Marchantia polymorpha, with antheridial and archegonial stalks. The archegonium of Porella. A sporophyte emerging from its archegonium. Porella platyphylla clump growing on a tree.
Pellia epiphylla, growing on moist soil. Plagiochila asplenioides, a leafy liverwort. Riccia fluitans, an aquatic thallose liverwort. Conocephalum conicum, a large thallose liverwort.

See also

References

  1. ^ a b VanAller Hernick, L.; Landing, E.; Bartowski, K.E. (2008). "Earth’s oldest liverworts—Metzgeriothallus sharonae sp. nov. from the Middle Devonian (Givetian) of eastern New York, USA". Review of Palaeobotany and Palynology 148: 154–162. doi:10.1016/j.revpalbo.2007.09.002.
  2. ^ Stotler, Raymond E.; Barbara J. Candall-Stotler (1977). "A checklist of the liverworts and hornworts of North America". The Bryologist 80: 405–428. doi:10.2307/3242017.
  3. ^ a b Crandall-Stotler, Barbara. & Stotler, Raymond E. "Morphology and classification of the Marchantiophyta". page 21 in A. Jonathan Shaw & Bernard Goffinet (Eds.), Bryophyte Biology. (Cambridge: Cambridge University Press:2000). ISBN 0-521-66097-1.
  4. ^ Schuster, Rudolf M. The Hepaticae and Anthocerotae of North America, volume VI, page 19. (Chicago: Field Museum of Natural History, 1992). ISBN 0-914-86821-7.
  5. ^ Schuster, Rudolf M. The Hepaticae and Anthocerotae of North America, volume I, pages 243-244. (New York: Columbia University Press, 1966)
  6. ^ Kashyap, Shiv Ram. Liverworts of the Western Himalayas and the Panjab Plain, volume I, page 1. (New Delhi: The Chronica Botanica, 1929)
  7. ^ a b c d Schofield, W. B. Introduction to Bryology, pages 135-140. (New York: Macmillan, 1985). ISBN 0-02-949660-8.
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  9. ^ Allison, K. W. & John Child. The Liverworts of New Zealand, pages 13-14. (Dunedin: University of Otago Press, 1975).
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  17. ^ a b Campbell, Douglas H. The Structure and Development of Mosses and Ferns, pages 73-74. (London: The Macmillan Co., 1918)
  18. ^ Schuster, Rudolf M. The Hepaticae and Anthocerotae of North America, volume I, pages 243-249. (New York: Columbia University Press, 1966).
  19. ^ Pócs, Tamás. "Tropical Forest Bryophytes", page 59 in A. J. E. Smith (Ed.) Bryophyte Ecology. (London: Chapman and Hall, 1982). ISBN 0-412-22340-6.
  20. ^ Crandall-Stotler, Barbara. & Stotler, Raymond E. "Morphology and classification of the Marchantiophyta". page 36-38 in A. Jonathan Shaw & Bernard Goffinet (Eds.), Bryophyte Biology. (Cambridge: Cambridge University Press:2000). ISBN 0-521-66097-1
  21. ^ Goffinet, Bernard. "Origin and phylogenetic relationships of bryophytes". pages 124-149 in A. Jonathan Shaw & Bernard Goffinet (Eds.), Bryophyte Biology. (Cambridge: Cambridge University Press:2000). ISBN 0-521-66097-1
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  25. ^ Crandall-Stotler, Barbara. & Stotler, Raymond E. "Morphology and classification of the Marchantiophyta". page 63 in A. Jonathan Shaw & Bernard Goffinet (Eds.), Bryophyte Biology. (Cambridge: Cambridge University Press:2000). ISBN 0-521-66097-1
  26. ^ a b Forrest, Laura L.; Christine E. Davis, David G. Long, Barbara J. Crandall-Stotler, Alexandra Clark & Michelle L. Hollingsworth (2006). "Unraveling the evolutionary history of the liverworts (Marchantiophyta): multiple taxa, genomes and analyses". The Bryologist 109 (3): 303–334. doi:10.1639/0007-2745(2006)109[303:UTEHOT]2.0.CO;2.
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External links

Wikimedia Commons has media related to: Marchantiophyta
Wikispecies has information related to: Marchantiophyta
Look up liverwort in Wiktionary, the free dictionary.
Classification of Archaeplastida / Plantae sensu lato
Rhodophyta Rhodophyceae · Bangiophyceae · Florideophyceae · Goniotrichales · Stylonematophyceae
Glaucocystophyceae Glaucocystis · Cyanophora · Gloeochaete
Viridiplantae/ Plantae sensu stricto
Chlorophyta/GA Bryopsidophyceae · Chlorophyceae · Pedinophyceae · Pleurastrophyceae · Prasinophyceae · Trebouxiophyceae · Ulvophyceae
Streptophyta
Charophyta/GA
Charophyceae Charales
Coleochaetophyceae Coleochaetales
Zygnematophyceae Desmidiales · Zygnematales
Embryophyta/ Plantae sensu strictissimo
Bryophytes (non-vascular) Marchantiophyta · Anthocerotophyta · Bryophyta "Moss" · Horneophytopsida
Tracheophyta
Lycopodiophyta Isoetopsida (Isoetales, Selaginellales) · Lycopodiopsida (Lycopodiales)
Euphyllophyta Moniliformopses (Equisetopsida, Filicopsida, Psilotopsida) Spermatophyta: Gymnosperm (Pinophyta, Cycadophyta, Ginkgophyta, Gnetophyta) · Magnoliophyta
see also list of plant orders

Categories: Liverworts

 

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