Horneophytopsida is a class of early vascular plants Vascular plants are those plants that have lignified tissues for conducting water, minerals, and photosynthetic products through the plant. Vascular plants include the ferns, clubmosses, flowering plants, conifers and other gymnosperms. Scientific names for the group include Tracheophyta and Tracheobionta, but neither name is very widely used.[ including the genera Caia, Tortilicaulis, and Horneophyton. Although formerly classified among the Rhyniophyta Rhyniophyta is a division of early vascular plants including the class Rhyniopsida. Its circumscription of included species has changed as additional information is revealed in the form of new fossils or new analysis. In particular, some specimens previously included in the group are now known to lack vascular tissue, and so cannot be included in, the group is distinctive for having branched sporangia A sporangium is a plant, fungal, or algal structure producing and containing spores. Sporangia occur in angiosperms, gymnosperms, ferns, fern allies, bryophytes, algae, and fungi. Their spores are sometimes called sporangiospores, and lacking true xylem In vascular plants, xylem is one of the two types of transport tissue, phloem being the other. The word "xylem" is derived from classical Greek ξυλον , "wood", and indeed the best known xylem tissue is wood, though it is found throughout the plant. Its basic function is to transport water.[1]

Cladogram of the land plants 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 showing the position of the "rhyniophytes" (in blue). Diagram based on Kenrick & Crane 1997. More recent molecular research reverses the position of the hornworts and mosses.[2]

References

  1. ^ a b Kenrick, Paul; Peter R. Crane (1997). The Origin and Early Diversification of Land Plants : A Cladistic Study. Washington, D.C.: Smithsonian Institution Press. pp. pp. 139-140, 249. ISBN 1-56098-730-8.
  2. ^ Qiu et al. 2006

See also

Polysporangiophytes Polysporangiophytes are plants with a structure of branching axes terminating in sporangia. This includes most land plants except for the bryophytes. Its definition is independent of the presence of vascular tissue. The earliest known polysporangiophytes are genera such as the famous Cooksonia and Aglaophyton

External links

Classification of Archaeplastida The Archaeplastida are a major line of eukaryotes, comprising the land plants, green and red algae, and a small group called the glaucophytes. All of these organisms have plastids surrounded by two membranes, suggesting they developed directly from endosymbiotic cyanobacteria. In all other groups, plastids are surrounded by three or four membranes, / Plantae sensu lato 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
Rhodophyta The red algae (or Rhodophyta, pronounced /roʊˈdɒfɨtə, ˌroʊdəˈfaɪtə/, from Greek: ῥόδον = rose + φυτόν (phyton) = plant, thus red plant) are one of the oldest groups of eukaryotic algae, and also one of the largest, with about 5,000–6,000 species of mostly multicellular, marine algae, including many notable seaweeds. Other Rhodophyceae · Bangiophyceae Bangiophyceae was a class of red algae; it has since been merged with the Floridophyceae to form the Rhodophyceae. The Bangiophyceae, as defined traditionally, are paraphyletic.. Their taxonomic identification has been difficult because of a lack of distinct morphological features, and the presumed morphological plasticity of the species · Florideophyceae Florideophyceae was a class of red algae. It is now merged with the Bangiaceae into the Rhodophyceae. They were once thought to be the only algae to bear pit connections, but these have since been found in the filamentous stage of the Bangiacae · Goniotrichales · Stylonematophyceae
Glaucocystophyceae The glaucophytes, also known as glaucocystophytes or glaucocystids, are a small group of freshwater microscopic algae. Together with the red algae and Viridiplantae they form the Archaeplastida. However, the relationships between the red algae, green algae and glaucophytes are unclear, in large part due to limited study of the glaucophytes Glaucocystis · Cyanophora · Gloeochaete
Viridiplantae In some classification systems they have been treated as a kingdom, under various names, e.g. Viridiplantae, Chlorobionta, or simply Plantae/ Plantae sensu stricto
Chlorophyta Chlorophyta, a division of green algae, includes about 7000 species of mostly aquatic photosynthetic eukaryotic organisms. Like the land plants , green algae contain chlorophylls a and b, and store food as starch in their plastids. They are related to the Charophyta and Embryophyta (land plants), together making up the Viridiplantae/GA The green algae are the large group of algae from which the embryophytes (higher plants) emerged. As such, they form a paraphyletic group, although the group including both green algae and embryophytes is monophyletic (and often just known as kingdom Plantae). The green algae include unicellular and colonial flagellates, usually but not always Bryopsidophyceae In taxonomy, the Bryopsidophyceae are a class of green algae, in the division Chlorophyta · Chlorophyceae The Chlorophyceae are one of the classes of green algae, distinguished mainly on the basis of ultrastructural morphology. For example the chlorophycean CW clade, and chlorophycean DO clade, are defined by the arrangement of their flagella. Members of the CW clade have flagella that are displaced in a "clockwise" direction eg · Pedinophyceae In taxonomy, the Pedinomonadaceae are a family of algae. They are small single-celled algae. Each cell has a single flagellum. It has been proposed to be either in the Mamiellales or the Ulvophyceae, but it has not been studied enough to confidently place it · Pleurastrophyceae In taxonomy, the Pleurastrophyceae are a class of green algae, in the division Chlorophyta. It was created by Mattox and Stewart in 1984, containing four genera. More recent classifications tend to split the group. On the one hand, Tetraselmis seems to be a sister to the so-called UTC clade , thus making it part of the (paraphyletic) · Prasinophyceae In taxonomy, Prasinophytes are a class of the Division Chlorophyta. These are primitive eukaryotic, marine green algae. Its best known genus is Ostreococcus , which is considered to be the smallest (ca. 0.95 μm) free-living eukaryote and which has been detected in marine samples around the world. Prasinophytes are thought to have low cellular · Trebouxiophyceae In taxonomy, the Trebouxiophyceae are a class of green algae, in the division Chlorophyta · Ulvophyceae
Streptophyta Streptophytina is formally a subdivision or subphylum which contains two classes: Charophyceae, containing the Charales order (Charophytes sensu stricto); and Embryophyceae, which contains the embryophytes (land plants, bryophytes, and vascular plants)
Charophyta/GA The green algae are the large group of algae from which the embryophytes (higher plants) emerged. As such, they form a paraphyletic group, although the group including both green algae and embryophytes is monophyletic (and often just known as kingdom Plantae). The green algae include unicellular and colonial flagellates, usually but not always
Charophyceae Charales
Coleochaetophyceae The Coleochaetales are a family of parenchymous charophyte algae. They questionably include the fossil genus Parka Coleochaetales
Zygnematophyceae Zygnematophyceae is an order of green algae. It contains two orders: Zygnematales and Desmidiales Desmidiales Desmids are an order of green algae, comprising around 40 genera and 5,000 to 6,000 species, found mostly but not exclusively in fresh water. Most are unicellular, and are divided into two compartments separated by a narrow bridge or isthmus. Desmids assume a variety of highly symmetrical and generally attractive shapes, which provide the basis · Zygnematales The Zygnematales (Greek: ζυγός + νήμα (nēma) (nom.), νήματος (nēmatos) (gen.)), also called the Conjugales, are an order of green algae, comprising several thousand different species in genera such as the well-known Zygnema and Spirogyra. All the members of this group develop into unbranched filaments, one cell thick, which grow
Embryophyta 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/ Plantae sensu strictissimo
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 & (non-vascular Non-vascular plants is a general term for those plants without a vascular system . Although non-vascular plants lack these particular tissues, a number of non-vascular plants possess tissues specialized for internal transport of water) Marchantiophyta · Anthocerotophyta 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 · Bryophyta "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 · Horneophytopsida
Tracheophyta Vascular plants are those plants that have lignified tissues for conducting water, minerals, and photosynthetic products through the plant. Vascular plants include the ferns, clubmosses, flowering plants, conifers and other gymnosperms. Scientific names for the group include Tracheophyta and Tracheobionta, but neither name is very widely used.[
Lycopodiophyta The Division Lycopodiophyta is a tracheophyte subdivision of the Kingdom Plantae. It is the oldest extant (living) vascular plant division at around 420 million years old,[citation needed] and includes some of the most "primitive" extant species. These species reproduce by shedding spores and have macroscopic alternation of generations, Isoetopsida The Isoetopsida is a class of the Lycopodiophyta. All living plants belong to the genus Isoetes in the order Isoetales. The order Isoetales is sometimes placed in the class Isoetopsida, sometimes in the Selaginellopsida or Lycopsida. There are about 140-150 species, with a cosmopolitan distribution but often scarce to rare. Some botanists split (Isoetales Isoëtes, also written Isoetes and commonly known as the quillworts, is the genus of plants in the class Isoetopsida and order Isoetales. The order Isoetales is sometimes placed in the class Isoetopsida, sometimes in the Selaginellopsida or Lycopsida. They are considered "fern allies". There are about 140-150 species, with a cosmopolitan, Selaginellales Selaginella is a genus of plants in the family Selaginellaceae, which includes Spikemoss. Many workers still place the Selaginellales in the class Lycopsida . This group of plants is included in what, for convenience, is called "fern allies". S. moellendorffii is an important model organism, and its genome was sequenced by the United) · Lycopodiopsida Lycopodiopsida is a class of plants often loosely grouped as the fern allies, and includes the clubmosses. Lycopodiopsida traditionally included all the clubmosses, including Selaginella and Isoetes. However, subdivisions within the Division Lycopodiophyta are now considered ancient enough to warrant higher-level separation in accordance with (Lycopodiales Lycopodiopsida is a class of plants often loosely grouped as the fern allies, and includes the clubmosses. Lycopodiopsida traditionally included all the clubmosses, including Selaginella and Isoetes. However, subdivisions within the Division Lycopodiophyta are now considered ancient enough to warrant higher-level separation in accordance with)
Euphyllophyta Euphyllophyta is a grouping of plants Moniliformopses (Equisetopsida Equisetopsida, or Sphenopsida, is a class of plants with a fossil record going back to the Devonian. Living species are commonly known as horsetails and typically grow in wet areas, with needle-like leaves radiating at regular intervals from a single vertical stem. Equisetopsida is placed in the botanical division of ferns , though sometimes, Filicopsida A fern is any one of a group of about 20,000 species of plants classified in the phylum or division Pteridophyta, also known as Filicophyta. The group is also referred to as Polypodiophyta, or Polypodiopsida when treated as a subdivision of tracheophyta . The term "pteridophyte" has traditionally been used to describe all seedless, Psilotopsida Psilotopsida is a class of fern-like plants. As circumscribed by Smith et al. it contains two families, Psilotaceae and Ophioglossaceae, placed in orders Psilotales and Ophioglossales, respectively. The affinities of these two groups have long been unclear and a close relationship between them has only recently been confirmed through molecular) Spermatophyta 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:: Gymnosperm Gymnosperm is a group of spermatophyte seed-bearing plants with ovules on scales, which are usually arranged in cone-like structures. The other major group of seed-bearing plants, the angiosperms, [from the Greek, 'angion' - container] have ovules enclosed in a carpel, a sporophyll with fused margins. A carpel consists of a stigma, style and the (Pinophyta The conifers, division Pinophyta, also known as division Coniferophyta or Coniferae, are one of 13 or 14 division level taxa within the Kingdom Plantae. Pinophytes are gymnosperms. They are cone-bearing seed plants with vascular tissue; all extant conifers are woody plants, the great majority being trees with just a few being shrubs. Typical, Cycadophyta Cycads are a group of seed plants characterized by a large crown of compound leaves and a stout trunk. They are evergreen, gymnospermous, dioecious plants having large pinnately compound leaves. They are frequently confused with and mistaken for palms or ferns, but are related to neither, belonging to the division Cycadophyta, Ginkgophyta The Ginkgoaceae is a family of gymnosperms which appeared during the Mesozoic Era, of which the only extant representative is Ginkgo biloba, which is for this reason sometimes regarded as a living fossil. Formerly, however, there were several other genera, Gnetophyta The plant division Gnetophyta or gnetophytes comprise three related families of woody plants grouped in the gymnosperms. The gnetophytes differ from other gymnosperms in having vessel elements as in the flowering plants) · Magnoliophyta The flowering plants or angiosperms are the most diverse group of land plants. The flowering plants and the gymnosperms are the only extant groups of seed plants. The flowering plants are distinguished from other seed plants by a series of apomorphies, or derived characteristics
see also list of plant orders

Categories: Prehistoric plants | Devonian life

 

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