32-545: See text Corystosperms are a group of extinct seed plants (often referred to as " seed ferns ") belonging to the family Corystospermaceae (also called Umkomasiaceae ) assigned to the order Corystospermales or Umkomasiales . They were first described based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. Corystosperms are typified by
64-406: A clade of gymnosperms , with the gnetophytes in or near the conifers. For example, one common proposed set of relationships is known as the gne-pine hypothesis and looks like: (flowering plants) [REDACTED] Cycads [REDACTED] Ginkgo [REDACTED] Pinaceae (the pine family) [REDACTED] Gnetophytes [REDACTED] other conifers [REDACTED] However,
96-495: A phanerogam (taxon Phanerogamae ) or a phaenogam (taxon Phaenogamae ), is any plant that produces seeds . It is a category of embryophyte (i.e. land plant) that includes most of the familiar land plants, including the flowering plants and the gymnosperms , but not ferns , mosses , or algae . The term phanerogam or phanerogamae is derived from the Greek φανερός ( phanerós ), meaning "visible", in contrast to
128-442: A woody stem ), grasses and grass-like plants, a vast majority of broad-leaved trees , shrubs and vines , and most aquatic plants . Angiosperms are distinguished from the other major seed plant clade, the gymnosperms , by having flowers , xylem consisting of vessel elements instead of tracheids , endosperm within their seeds, and fruits that completely envelop the seeds. The ancestors of flowering plants diverged from
160-454: A group of plants that bore forked Dicroidium leaves, Umkomasia cupulate ovulate structures and Pteruchus pollen organs, which grew as trees that were widespread over Gondwana during the Middle and Late Triassic . Other fossil Mesozoic seed plants with similar leaf and/or reproductive structures have also sometimes been included within the "corystosperm" concept sensu lato , such as
192-640: A new order to encompass the family, Corystospermales. Doweld (2001) preferred a different name for the order, Umkomasiales. He also added a second family, Angaropeltidaceae (previously known as Cardiolepidaceae). Later sources generally classify Angaropeltidaceae (or its updated spelling, Angaropeltaceae ) within Peltaspermales instead. Seed plant A seed plant or spermatophyte ( lit. ' seed plant ' ; from Ancient Greek σπέρματος ( spérmatos ) 'seed' and φυτόν (phytón) 'plant'), also known as
224-558: A system to guide the pollen to the seed. Runcaria was followed shortly after by plants with a more condensed cupule, such as Spermasporites and Moresnetia . Seed-bearing plants had diversified substantially by the Famennian , the last stage of the Devonian. Examples include Elkinsia , Xenotheca , Archaeosperma , " Hydrasperma ", Aglosperma , and Warsteinia . Some of these Devonian seeds are now classified within
256-610: A total of 64 angiosperm orders and 416 families. The diversity of flowering plants is not evenly distributed. Nearly all species belong to the eudicot (75%), monocot (23%), and magnoliid (2%) clades. The remaining five clades contain a little over 250 species in total; i.e. less than 0.1% of flowering plant diversity, divided among nine families. The 25 most species-rich of 443 families, containing over 166,000 species between them in their APG circumscriptions, are: The botanical term "angiosperm", from Greek words angeíon ( ἀγγεῖον 'bottle, vessel') and spérma ( σπέρμα 'seed'),
288-858: Is starting to impact plants and is likely to cause many species to become extinct by 2100. Angiosperms are terrestrial vascular plants; like the gymnosperms, they have roots , stems , leaves , and seeds . They differ from other seed plants in several ways. The largest angiosperms are Eucalyptus gum trees of Australia, and Shorea faguetiana , dipterocarp rainforest trees of Southeast Asia, both of which can reach almost 100 metres (330 ft) in height. The smallest are Wolffia duckweeds which float on freshwater, each plant less than 2 millimetres (0.08 in) across. Considering their method of obtaining energy, some 99% of flowering plants are photosynthetic autotrophs , deriving their energy from sunlight and using it to create molecules such as sugars . The remainder are parasitic , whether on fungi like
320-422: Is an integumented megasporangium surrounded by a cupule. The megasporangium bears an unopened distal extension protruding above the mutlilobed integument . It is suspected that the extension was involved in anemophilous (wind) pollination . Runcaria sheds new light on the sequence of character acquisition leading to the seed. Runcaria has all of the qualities of seed plants except for a solid seed coat and
352-608: Is highly variable, going from simple to tripinnate , to needle-like to lobed or dissected leaflets, however, all leaves are united by being bifurcated at the base. The Dicroidium plant (which bore Dicroidium leaves, Umkomasia seed bearing structures and Pteruchus pollen organs) is thought to have grown as large trees , with trunks at least 10 metres (33 ft) tall and over 50 centimetres (20 in) wide. Some other possible corystosperms like Pachypteris may have grown as shrubs . The oldest fossils of corystosperms, belonging to Dicroidium, Pteruchus and Umkomasia date to
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#1732782361010384-481: Is the flowering plants , also known as angiosperms or magnoliophytes, the largest and most diverse group of spermatophytes: In addition to the five living taxa listed above, the fossil record contains evidence of many extinct taxa of seed plants, among those: By the Triassic period, seed ferns had declined in ecological importance, and representatives of modern gymnosperm groups were abundant and dominant through
416-491: The Alismatales grow in marine environments, spreading with rhizomes that grow through the mud in sheltered coastal waters. Some specialised angiosperms are able to flourish in extremely acid or alkaline habitats. The sundews , many of which live in nutrient-poor acid bogs , are carnivorous plants , able to derive nutrients such as nitrate from the bodies of trapped insects. Other flowers such as Gentiana verna ,
448-611: The Petriellales , Caytoniales , and glossopterids . Corystospermaceae is a family name which was not derived from a specific genus, an arrangement which is discouraged by the ICN . In light of this issue, Petriella (1981) proposed two solutions: either retain Corystospermaceae as a nomen conservandum , or replace it with a new name, Umkomasiaceae. Both names have been used frequently since then. Petriella additionally named
480-526: The canopy vegetation. Dicroidium- bearing corystosperm ecosystems collapsed as a result of the end-Triassic extinction event . Late surviving Dicroidium -bearing corystosperms are known from the Early Jurassic ( Sinemurian ) of East Antarctica. During the Jurassic, the possible corystosperms Pachypteris and Komlopteris were widespread over both hemispheres, with Komlopteris surviving in
512-533: The clade Angiospermae ( / ˌ æ n dʒ i ə ˈ s p ər m iː / ). The term 'angiosperm' is derived from the Greek words ἀγγεῖον / angeion ('container, vessel') and σπέρμα / sperma ('seed'), meaning that the seeds are enclosed within a fruit. The group was formerly called Magnoliophyta . Angiosperms are by far the most diverse group of land plants with 64 orders , 416 families , approximately 13,000 known genera and 300,000 known species . They include all forbs (flowering plants without
544-460: The orchids for part or all of their life-cycle, or on other plants , either wholly like the broomrapes, Orobanche , or partially like the witchweeds, Striga . In terms of their environment, flowering plants are cosmopolitan, occupying a wide range of habitats on land, in fresh water and in the sea. On land, they are the dominant plant group in every habitat except for frigid moss-lichen tundra and coniferous forest . The seagrasses in
576-892: The "Big Five" extinction events in Earth's history, only the Cretaceous–Paleogene extinction event had occurred while angiosperms dominated plant life on the planet. Today, the Holocene extinction affects all kingdoms of complex life on Earth, and conservation measures are necessary to protect plants in their habitats in the wild ( in situ ), or failing that, ex situ in seed banks or artificial habitats like botanic gardens . Otherwise, around 40% of plant species may become extinct due to human actions such as habitat destruction , introduction of invasive species , unsustainable logging , land clearing and overharvesting of medicinal or ornamental plants . Further, climate change
608-729: The "doyleoids" from the Early Cretaceous of North America and Asia. A potential corystosperm sensu lato , the leaf genus Komlopteris , is known from the Eocene of Tasmania, around 53-50 million years old, over 10 million years after the Cretaceous–Paleogene extinction event . Classic Umkomasiaceae have helmet-like cupules around ovules born in complex large branching structures ( Umkomasia ). The pollen organ ( Pteruchus ) has numerous cigar-shaped pollen sacs hanging from epaulette-like blades, again in complex branching structures. The architecture and size of Dicroidium leaves
640-543: The Early Jurassic. The relationships of corystosperms to other seed plants are contentious. It has been suggested that some " peltasperms " may be closely related to corystosperms. A 2016 paper suggested that they may be closely related to Ginkgoales , while a 2021 study suggested that based on the structure of their ovulate organs, corystosperms might form part of the " Anthophyte " clade more closely related to flowering plants than to living gymnosperms , alongside
672-816: The Late Permian in the low-latitudes of eastern Gondwana , including the Umm Irna Formation of Jordan, as well as the Indian subcontinent, though possible pollen belonging to the group is also known from the Late Permian of South Africa. During the Middle-Late Triassic, Dicroidium bearing corystosperms were widespread and dominant trees over temperate areas of southern Gondwana (including the Indian subcontinent, South America, Southern Africa, Antarctica, Australia and New Zealand) including wetland and forest environments, where they formed part of
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#1732782361010704-674: The Southern Hemisphere through the Cretaceous and into the early Eocene in Tasmania, making it the last surviving "seed fern" in the fossil record. A group of plants with corystosperm-like reproductive structures, either considered corystosperms or as belonging to the separate order Doyleales, were present in North America and Asia during the Early Cretaceous, with records of the group possibly extending back as far as
736-560: The common ancestor of all living gymnosperms before the end of the Carboniferous , over 300 million years ago. In the Cretaceous , angiosperms diversified explosively , becoming the dominant group of plants across the planet. Agriculture is almost entirely dependent on angiosperms, and a small number of flowering plant families supply nearly all plant-based food and livestock feed. Rice , maize and wheat provide half of
768-494: The end of the Cretaceous , when the angiosperms radiated. A whole genome duplication event in the ancestor of seed plants occurred about 319 million years ago . This gave rise to a series of evolutionary changes that resulted in the origin of modern seed plants. A middle Devonian (385-million-year-old) precursor to seed plants from Belgium has been identified predating the earliest seed plants by about 20 million years. Runcaria , small and radially symmetrical,
800-659: The flowering plants as an unranked clade without a formal Latin name (angiosperms). A formal classification was published alongside the 2009 revision in which the flowering plants rank as the subclass Magnoliidae. From 1998, the Angiosperm Phylogeny Group (APG) has reclassified the angiosperms, with updates in the APG II system in 2003, the APG III system in 2009, and the APG IV system in 2016. In 2019,
832-518: The manner of vines or lianas . The number of species of flowering plants is estimated to be in the range of 250,000 to 400,000. This compares to around 12,000 species of moss and 11,000 species of pteridophytes . The APG system seeks to determine the number of families , mostly by molecular phylogenetics . In the 2009 APG III there were 415 families. The 2016 APG IV added five new orders (Boraginales, Dilleniales, Icacinales, Metteniusales and Vahliales), along with some new families, for
864-540: The order Lyginopteridales . Seed-bearing plants are a clade within the vascular plants (tracheophytes). The spermatophytes were traditionally divided into angiosperms , or flowering plants, and gymnosperms , which includes the gnetophytes, cycads, ginkgo, and conifers. Older morphological studies believed in a close relationship between the gnetophytes and the angiosperms, in particular based on vessel elements . However, molecular studies (and some more recent morphological and fossil papers) have generally shown
896-619: The relationships between these groups should not be considered settled. Other classifications group all the seed plants in a single division , with classes for the five groups: A more modern classification ranks these groups as separate divisions (sometimes under the Superdivision Spermatophyta ): Unassigned extinct spermatophyte orders, some of which qualify as "seed ferns": Flowering plant Basal angiosperms Core angiosperms Flowering plants are plants that bear flowers and fruits , and form
928-568: The spring gentian, are adapted to the alkaline conditions found on calcium -rich chalk and limestone , which give rise to often dry topographies such as limestone pavement . As for their growth habit , the flowering plants range from small, soft herbaceous plants , often living as annuals or biennials that set seed and die after one growing season, to large perennial woody trees that may live for many centuries and grow to many metres in height. Some species grow tall without being self-supporting like trees by climbing on other plants in
960-484: The term "cryptogam" or " cryptogamae " (from Ancient Greek κρυπτός (kruptós) 'hidden'), together with the suffix γαμέω ( gaméō ), meaning "to marry". These terms distinguish those plants with hidden sexual organs (cryptogamae) from those with visible ones (phanerogamae). The extant spermatophytes form five divisions, the first four of which are classified as gymnosperms , plants that have unenclosed, "naked seeds": The fifth extant division
992-559: The world's staple calorie intake, and all three plants are cereals from the Poaceae family (colloquially known as grasses). Other families provide important industrial plant products such as wood , paper and cotton , and supply numerous ingredients for beverages , sugar production , traditional medicine and modern pharmaceuticals . Flowering plants are also commonly grown for decorative purposes , with certain flowers playing significant cultural roles in many societies. Out of
Corystospermaceae - Misplaced Pages Continue
1024-483: Was coined in the form "Angiospermae" by Paul Hermann in 1690, including only flowering plants whose seeds were enclosed in capsules. The term angiosperm fundamentally changed in meaning in 1827 with Robert Brown , when angiosperm came to mean a seed plant with enclosed ovules. In 1851, with Wilhelm Hofmeister 's work on embryo-sacs, Angiosperm came to have its modern meaning of all the flowering plants including Dicotyledons and Monocotyledons. The APG system treats
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