View source for Biology:Embryophyte

{{Short description|Subclade of green plants, also known as land plants}}
{{Automatic taxobox
| name = Land plants
| fossil_range = {{fossil range|Mid Ordovician|Present|earliest=Dapingian|PS=|ref=<ref name=Gray1985>{{Citation |last1=Gray |first1=J. |last2=Chaloner |first2=W.G. |last3=Westoll |first3=T.S. |year=1985 |title=The Microfossil Record of Early Land Plants: Advances in Understanding of Early Terrestrialization, 1970-1984 [and Discussion] |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=309 |pages=167–195 |doi=10.1098/rstb.1985.0077 |name-list-style=amp|bibcode=1985RSPTB.309..167G |issue=1138|doi-access=free }}</ref><ref>{{Citation |last1=Rubinstein |first1=C.V. |last2=Gerrienne |first2=P. |last3=De La Puente |first3=G.S. |last4=Astini |first4=R.A. |last5=Steemans |first5=P. |year=2010 |title=Early Middle Ordovician evidence for land plants in Argentina (eastern Gondwana) |journal=New Phytologist |volume=188 |issue=2 |doi=10.1111/j.1469-8137.2010.03433.x |pmid=20731783 |name-list-style=amp|pages=365–9 |doi-access=free |hdl=11336/55341 |hdl-access=free }}</ref>}} <small>(Spores from Dapingian (early Middle Ordovician))</small>
|image={{Multiple image
|perrow          = 2
|total_width     = 270
|image1          = WWB-0265-127-Polytrichum_formosum.png
|caption1        = [[Biology:Moss|Moss]]
|image2          = Frühling blühender Kirschenbaum.jpg
|caption2        = [[Biology:Angiosperm|Angiosperm]]
|image3          = Fern detail.jpg
|caption3        = [[Biology:Fern|Fern]]
|image4          = Phaeoceros_laevis_48205337_(white_background).jpg
|caption4        = [[Biology:Hornwort|Hornwort]]
|image5          = PIH_1830_Scots_Pine_(Pinus_sylvestris)_graft_clone_collection_in_R%C3%B6ykk%C3%A4_Finland.jpg
|caption5        = [[Biology:Gymnosperm|Gymnosperm]]
|image6          = Lycopodium saururus.JPG
|caption6        = [[Biology:Lycopodiopsida|Lycophyte]]
|border          = infobox
}}
| taxon = Embryophytes/Plantae
| authority = Engler, 1892<ref>Engler, A. 1892. ''Syllabus der Vorlesungen über specielle und medicinisch-pharmaceutische Botanik: Eine Uebersicht über das ganze Pflanzensystem mit Berücksichtigung der Medicinal- und Nutzpflanzen.'' Berlin: Gebr. Borntraeger.</ref><ref>{{cite journal |last1=Pirani |first1=J. R. |last2=Prado |first2=J. |year=2012 |title=Embryopsida, a new name for the class of land plants |url=https://www.researchgate.net/publication/257929335 |format=PDF |journal=Taxon |volume=61 |issue=5 |pages=1096–1098 |doi=10.1002/tax.615014 }}</ref>
| subdivision_ranks = Divisions
| subdivision = * '''[[Biology:Bryophyte|Non-vascular land plants]] (bryophytes)'''
** [[Biology:Marchantiophyta|Marchantiophyta]] – liverworts
** [[Biology:Moss|Bryophyta]] – mosses
** [[Biology:Hornwort|Anthocerotophyta]] – hornworts
** †[[Biology:Horneophytopsida|Horneophytopsida]]
* '''[[Biology:Vascular plant|Vascular plant]]s (tracheophytes)'''
** †Rhyniophyta – rhyniophytes
** †[[Biology:Zosterophyll|Zosterophyll]]ophyta – zosterophylls
** [[Biology:Lycopodiopsida|Lycopodiophyta]] – clubmosses
** †Trimerophytophyta – trimerophytes
** [[Biology:Fern|Polypodiophyta]] – ferns and horsetails
** '''Seed plants (spermatophytes)'''
*** †[[Biology:Pteridospermatophyta|Pteridospermatophyta]] – seed ferns
*** [[Biology:Pinophyta|Pinophyta]] – conifers
*** [[Biology:Cycad|Cycad]]ophyta – cycads
*** [[Biology:Ginkgophyta|Ginkgophyta]] – ginkgo
*** [[Biology:Gnetophyta|Gnetophyta]] – gnetae
*** [[Biology:Flowering plant|Magnoliophyta]] – flowering plants
----
Traditional groups:
* [[Biology:Bryophyte|Bryophyta]]* 
* [[Biology:Pteridophyta|Pteridophyta]]*
* Gymnospermae*
* Angiospermae
| synonyms = * Cormophyta <small>[[Biography:Stephan Endlicher|Endlicher]], 1836</small>
* Phyta <small>Barkley, 1939</small><ref>Barkley, Fred A. ''Keys to the phyla of organisms''. Missoula, Montana. 1939.</ref>
* Cormobionta <small>Rothmaler, 1948</small><ref>Rothmaler, Werner. Über das natürliche System der Organismen. ''Biologisches Zentralblatt.'' 67: 242-250. 1948.</ref>
* Euplanta <small>Barkley, 1949</small><ref>{{cite journal | last1 = Barkley | first1 = Fred A | title = Un esbozo de clasificación de los organismos | url = http://www.bdigital.unal.edu.co/30839/ | journal = Revista de la Facultad Nacional de Agronomia, Universidad de Antioquia, Medellín | volume = 10 | pages = 83–103 }}</ref>
* Telomobionta <small>Takhtajan, 1964</small><ref>{{cite journal | last1 = Takhtajan | first1 = A | year = 1964 | title = The taxa of the higher plants above the rank of order | url = http://www.iapt-taxon.org/historic/Congress/IBC_1964/above_order.pdf | journal = Taxon | volume = 13 | issue = 5| pages = 160–164 | doi = 10.2307/1216134 | jstor = 1216134 }}</ref>
* Embryobionta <small>Cronquist et al. 1966</small><ref>{{cite journal | last1 = Cronquist | first1 = A. | last2 = Takhtajan | first2 = A. | last3 = Zimmermann | first3 = W. | year = 1966 | title = On the Higher Taxa of Embryobionta | url = http://www.iapt-taxon.org/historic/Congress/IBC_1969/embryobionta.pdf | journal = Taxon | volume = 15 | issue = 4| pages = 129–134 | doi=10.2307/1217531| jstor = 1217531 }}</ref>
* Metaphyta <small>Whittaker, 1969</small><ref>{{cite journal | last1 = Whittaker | first1 = R. H. | year = 1969 | title = New concepts of kingdoms or organisms | url = http://www.ib.usp.br/inter/0410113/downloads/Whittaker_1969.pdf | journal = Science | volume = 163 | issue = 3863 | pages = 150–160 | doi = 10.1126/science.163.3863.150 | bibcode = 1969Sci...163..150W | pmid = 5762760 | citeseerx = 10.1.1.403.5430 | access-date = 2014-11-28 | archive-url = https://web.archive.org/web/20171117160137/http://www.ib.usp.br/inter/0410113/downloads/Whittaker_1969.pdf | archive-date = 2017-11-17 | url-status = dead }}</ref>
* Plantae <small>[[Biography:Lynn Margulis|Margulis]], 1971</small><ref>{{cite journal | last1 = Margulis | first1 = L | year = 1971 | title = Whittaker's five kingdoms of organisms: minor revisions suggested by considerations of the origin of mitosis | journal = Evolution | volume = 25 | issue = 1| pages = 242–245 | doi=10.2307/2406516| pmid = 28562945 | jstor = 2406516 }}</ref>
}}
The '''embryophytes''' ({{IPAc-en|ˈ|ɛ|m|b|r|i|ə|ˌ|f|aɪ|t|s}}) are a [[Biology:Clade|clade]] of plants, also known as '''Embryophyta''' ({{IPAc-en|ˌ|ɛ|m|b|r|i|ˈ|ɒ|f|ə|t|ə|,_|-|oʊ|ˈ|f|aɪ|t|ə}}) or '''land plants'''. They are the most familiar group of photoautotrophs that make up the [[Biology:Vegetation|vegetation]] on [[Astronomy:Earth|Earth]]'s dry lands and [[Earth:Wetland|wetland]]s. Embryophytes ({{IPAc-en|ˈ|ɛ|m|b|r|i|ə|ˌ|f|aɪ|t|s}}) have a common ancestor with [[Biology:Green algae|green algae]], having emerged within the [[Biology:Phragmoplastophyta|Phragmoplastophyta]] clade of freshwater charophyte green algae as a sister taxon of [[Biology:Charophyceae|Charophyceae]], [[Biology:Coleochaetophyceae|Coleochaetophyceae]] and [[Biology:Zygnematophyceae|Zygnematophyceae]].<ref>{{Cite journal |last1=Delwiche |first1=Charles F. |last2=Timme |first2=Ruth E. |date=2011-06-07 |title=Plants |journal=Current Biology |volume=21 |issue=11 |pages=R417–R422 |doi=10.1016/j.cub.2011.04.021 |pmid=21640897 |s2cid=235312105 |issn=0960-9822|doi-access=free }}</ref> Embryophytes consist of the [[Biology:Bryophyte|bryophyte]]s and the [[Biology:Polysporangiophyte|polysporangiophyte]]s.<ref name="Puttick-2018" /> Living embryophytes include [[Biology:Hornwort|hornwort]]s, liverworts, [[Biology:Moss|moss]]es, [[Biology:Lycophyte|lycophyte]]s, [[Biology:Fern|fern]]s, [[Biology:Gymnosperm|gymnosperm]]s and [[Biology:Angiosperm|angiosperm]]s ([[Biology:Flowering plant|flowering plant]]s). Embryophytes have [[Biology:Biological life cycle|diplobiontic life cycle]]s.<ref>{{cite journal |last1=Gerrienne |first1=Philippe |last2=Gonez |first2=Paul |title=Early evolution of life cycles in embryophytes: A focus on the fossil evidence of gametophyte/sporophyte size and morphological complexity |journal=Journal of Systematics and Evolution |date=January 2011 |volume=49 |issue=1 |pages=1–16 |doi=10.1111/j.1759-6831.2010.00096.x|hdl=2268/101745 |s2cid=29795245 |hdl-access=free }}</ref>  

The embryophytes are informally called "land plants" because they thrive primarily in [[Earth:Terrestrial ecosystem|terrestrial habitat]]s (despite [[Biology:Aquatic plant|some members]] having evolved secondarily to live once again in [[Biology:Semiaquatic|semiaquatic]]/aquatic habitats), while the related green algae are primarily aquatic. Embryophytes are complex multicellular [[Biology:Eukaryote|eukaryote]]s with specialized reproductive organs. The name derives from their innovative characteristic of nurturing the young embryo [[Biology:Sporophyte|sporophyte]] during the early stages of its multicellular development within the tissues of the parent [[Biology:Gametophyte|gametophyte]]. With very few exceptions, embryophytes obtain biological energy by [[Earth:Photosynthesis|photosynthesis]], using [[Chemistry:Chlorophyll a|chlorophyll a]] and [[Chemistry:Chlorophyll b|b]] to harvest the light energy in [[Astronomy:Sunlight|sunlight]] for [[Earth:Biological carbon fixation|carbon fixation]] from [[Chemistry:Carbon dioxide|carbon dioxide]] and [[Chemistry:Water|water]] in order to synthesize [[Chemistry:Carbohydrate|carbohydrate]]s while releasing [[Chemistry:Oxygen|oxygen]] as a byproduct.

==Description==
[[File:Garden Primeval - US Botanic Gardens 37.jpg|thumb |Moss, clubmoss, ferns and cycads in a greenhouse]]
The Embryophytes emerged a half-billion years ago, at some time in the interval between the mid-[[Earth:Cambrian|Cambrian]] and early [[Earth:Ordovician|Ordovician]], probably from freshwater charophytes, a clade of multicellular [[Biology:Green algae|green algae]] similar to extant [[Biology:Klebsormidiophyceae|Klebsormidiophyceae]].<ref>{{cite journal |last1=Frangedakis |first1=Eftychios |last2=Shimamura |first2=Masaki |last3=Villarreal |first3=Juan Carlos |last4=Li |first4=Fay‐Wei |last5=Tomaselli |first5=Marta |last6=Waller |first6=Manuel |last7=Sakakibara |first7=Keiko |last8=Renzaglia |first8=Karen S. |last9=Szövényi |first9=Péter |title=The hornworts: morphology, evolution and development |journal=New Phytologist |date=January 2021 |volume=229 |issue=2 |pages=735–754 |doi=10.1111/nph.16874 |pmid=32790880 |pmc=7881058 }}</ref><ref name="NiklasKutschera2010">{{Citation |last1=Niklas |first1=K.J. |last2=Kutschera |first2=U. |year=2010 |title=The evolution of the land plant life cycle |journal=New Phytologist |volume=185 |issue=1 |pages=27–41 |doi=10.1111/j.1469-8137.2009.03054.x |pmid=19863728 |postscript=. |doi-access=free }}</ref><ref>{{cite journal |last1=de Vries |first1=J |last2=Archibald |first2=JM |title=Plant evolution: landmarks on the path to terrestrial life. |journal=The New Phytologist |date=March 2018 |volume=217 |issue=4 |pages=1428–1434 |doi=10.1111/nph.14975 |pmid=29318635 |doi-access=free}}</ref><ref>{{Cite journal |last=Del-Bem |first=Luiz-Eduardo |date=2018-05-31 |title=Xyloglucan evolution and the terrestrialization of green plants |journal=New Phytologist |language=en |volume=219 |issue=4 |pages=1150–1153 |doi=10.1111/nph.15191 |pmid=29851097 |issn=0028-646X |doi-access=free|hdl=1843/36860 |hdl-access=free }}</ref> The emergence of the Embryophytes depleted atmospheric CO<sub>2</sub> (a [[Chemistry:Greenhouse gas|greenhouse gas]]), leading to [[Earth:Ice age|global cooling]], and thereby precipitating glaciations.<ref>{{cite journal |last1=Donoghue |first1=Philip C.J. |last2=Harrison |first2=C. Jill |last3=Paps |first3=Jordi |last4=Schneider |first4=Harald |title=The evolutionary emergence of land plants |journal=Current Biology |date=October 2021 |volume=31 |issue=19 |pages=R1281–R1298 |doi=10.1016/j.cub.2021.07.038 |pmid=34637740 |s2cid=238588736 |hdl=1983/662d176e-fcf4-40bf-aa8c-5694a86bd41d |hdl-access=free }}</ref> Embryophytes are primarily adapted for life on land, although some are secondarily [[Biology:Aquatic plant|aquatic]]. Accordingly, they are often called land plants or terrestrial plants.{{cn|date=October 2023}}

On a microscopic level, the cells of charophytes are broadly similar to those of chlorophyte green algae, but differ in that in cell division the daughter nuclei are separated by a [[Biology:Phragmoplast|phragmoplast]].<ref name=Pickett-Heaps1976>{{cite journal | last1 = Pickett-Heaps | first1 = J. | year = 1976 | title = Cell division in eucaryotic algae | journal = BioScience | volume = 26 | issue = 7 | pages = 445–450 | doi=10.2307/1297481 | jstor = 1297481 }}</ref> They are [[Biology:Eukaryote|eukaryotic]], with a [[Biology:Cell wall|cell wall]] composed of [[Chemistry:Cellulose|cellulose]] and [[Biology:Plastid|plastid]]s surrounded by two membranes. The latter include [[Biology:Chloroplast|chloroplast]]s, which conduct photosynthesis and store food in the form of [[Chemistry:Starch|starch]], and are characteristically pigmented with chlorophylls ''a'' and ''b'', generally giving them a bright green color. Embryophyte cells also generally have an enlarged central [[Biology:Vacuole|vacuole]] enclosed by a vacuolar membrane or tonoplast, which maintains cell turgor and keeps the plant rigid.

In common with all groups of multicellular algae they have a life cycle which involves '[[Biology:Alternation of generations|alternation of generations]]'. A multicellular generation with a single set of [[Biology:Chromosome|chromosome]]s – the [[Biology:Haploid|haploid]] [[Biology:Gametophyte|gametophyte]] – produces sperm and eggs which fuse and grow into a multicellular generation with twice the number of chromosomes – the diploid [[Biology:Sporophyte|sporophyte]]. The mature sporophyte produces haploid [[Biology:Spore|spore]]s which grow into a gametophyte, thus completing the cycle. Embryophytes have two features related to their reproductive cycles which distinguish them from all other plant lineages. Firstly, their gametophytes produce sperm and eggs in multicellular structures (called '[[Biology:Antheridium|antheridia]]' and '[[Biology:Archegonium|archegonia]]'), and fertilization of the ovum takes place within the archegonium rather than in the external environment. Secondly, and most importantly, the initial stage of development of the fertilized egg (the [[Biology:Zygote|zygote]]) into a diploid multicellular sporophyte, takes place within the archegonium where it is both protected and provided with nutrition. This second feature is the origin of the term 'embryophyte' – the fertilized egg develops into a protected embryo, rather than dispersing as a single cell.<ref name="NiklasKutschera2010"/> In the [[Biology:Bryophyte|bryophyte]]s the sporophyte remains dependent on the gametophyte, while in all other embryophytes the sporophyte generation is dominant and capable of independent existence.

Embryophytes also differ from algae by having [[Biology:Metamerism|metamers]]. Metamers are repeated units of development, in which each unit derives from a single cell, but the resulting product tissue or part is largely the same for each cell. The whole organism is thus constructed from similar, repeating parts or ''metamers''. Accordingly, these plants are sometimes termed 'metaphytes' and classified as the group Metaphyta<ref>{{citation |last=Mayr |first=E. |year=1990 |title=A natural system of organisms |journal=Nature |volume=348 |page=491 |bibcode= 1990Natur.348..491M |doi= 10.1038/348491a0 |issue=6301 |s2cid=13454722 |doi-access=free }}</ref> (but Haeckel's definition of Metaphyta places some algae in this group<ref>{{cite web |url=https://archive.org/details/systematischephy01haec |title=Systematische phylogenie |first=Ernst Heinrich Philipp August |last=Haeckel |date=28 September 1894 |publisher=Berlin : Georg Reimer |via=Internet Archive}}</ref>). In all land plants a disc-like structure called a [[Biology:Phragmoplast|phragmoplast]] forms where the cell will [[Biology:Cytokinesis#Plant Cell Cytokinesis|divide]], a trait only found in the land plants in the streptophyte lineage, some species within their relatives [[Biology:Coleochaetales|Coleochaetales]], [[Biology:Charales|Charales]] and [[Biology:Zygnematales|Zygnematales]], as well as within [[Earth:Subaerial|subaerial]] species of the algae order [[Biology:Trentepohliales|Trentepohliales]], and appears to be essential in the adaptation towards a terrestrial life style.<ref>{{cite journal |url=http://www.nature.com/news/2001/010219/full/conference010222-8.html |title=Land plants divided and ruled |first=Whitfield |last=John |date=19 February 2001 |journal=Nature News |pages=conference010222–8 |doi=10.1038/conference010222-8}}</ref><ref>{{cite web |url=http://ijs.sgmjournals.org/content/53/6/1715.short |title=Phragmoplastin, green algae and the evolution of cytokinesis}}</ref><ref>{{cite web |url=http://news.sciencemag.org/sciencenow/2001/02/19-04.html |title=Invasions of the Algae - ScienceNOW - News - Science |access-date=2013-03-27 |archive-url=https://web.archive.org/web/20130602060506/http://news.sciencemag.org/sciencenow/2001/02/19-04.html |archive-date=2013-06-02 |url-status=dead}}</ref><ref>{{Cite web |url=http://news.nationalgeographic.com/news/2001/06/0604_wirealgae.html |archive-url=https://web.archive.org/web/20020126211113/http://news.nationalgeographic.com/news/2001/06/0604_wirealgae.html |url-status=dead |archive-date=January 26, 2002 |title=All Land Plants Evolved From Single Type of Algae, Scientists Say}}</ref>

== Evolution ==
The green algae and land plants form a [[Biology:Clade|clade]], the [[Viridiplantae]]. According to [[Biology:Molecular clock|molecular clock]] estimates, the Viridiplantae split {{mya|1200}} to {{mya|725}} into two clades: chlorophytes and streptophytes. The chlorophytes, with around 700 genera, were originally marine algae, although some groups have since spread into [[Earth:Fresh water|fresh water]]. The streptophyte algae (i.e. excluding the land plants) have around 122 genera; they adapted to fresh water very early in their evolutionary history and have not spread back into marine environments.{{cn|date=October 2023}}

Some time during the [[Earth:Ordovician|Ordovician]], streptophytes invaded the land and began the evolution of the embryophyte land plants.<ref name="BeckerMarin2009">{{Citation |last1=Becker |first1=B. |last2=Marin |first2=B. |year=2009 |title=Streptophyte algae and the origin of embryophytes |journal=Annals of Botany |volume=103 |issue=7 |pages=999–1004 |doi=10.1093/aob/mcp044 |name-list-style=amp|pmid=19273476 |pmc=2707909}}</ref> Present day embryophytes form a clade.<ref>{{Cite book|url=https://archive.org/details/treeoflifephylog0000leco |url-access=registration |page=[https://archive.org/details/treeoflifephylog0000leco/page/175 175] |quote=The hemitracheophytes form a monophyletic group that unites the bryophytes and the tracheophytes (or vascular plants) |title=The Tree of Life: A Phylogenetic Classification|first1=Guillaume |last1=Lecointre |first2=Hervé Le |last2=Guyader |date=August 28, 2006 |publisher=Harvard University Press |isbn=978-0-6740-2183-9}}</ref>
Becker and Marin speculate that land plants evolved from streptophytes because living in fresh water pools [[Biology:Exaptation|pre-adapted]] them to tolerate a range of environmental conditions found on land, such as exposure to rain, tolerance of temperature variation, high levels of ultra-violet light, and seasonal dehydration.<ref>{{Harvnb|Becker|Marin|2009|p=1001}}</ref>

The preponderance of molecular evidence as of 2006 suggested that the groups making up the embryophytes are related as shown in the cladogram below (based on Qiu ''et al.'' 2006 with additional names from Crane ''et al.'' 2004).<ref name="pmid17030812">{{Citation |last1=Qiu |first1=Y.L. |last2=Li |first2=L. |last3=Wang |first3=B. |last4=Chen |first4=Z. |year=2006 |title=The deepest divergences in land plants inferred from phylogenomic evidence |journal=Proceedings of the National Academy of Sciences |volume=103 |issue=42 |pages=15511–6 |doi=10.1073/pnas.0603335103 |pmid=17030812 |pmc=1622854 |bibcode= 2006PNAS..10315511Q |display-authors=0|doi-access=free }}</ref><ref>{{citation |last1=Crane |first1=P.R. |last2=Herendeen |first2=P. |last3=Friis |first3=E.M. |year=2004 |title=Fossils and plant phylogeny |journal=American Journal of Botany |volume=91 |pages=1683–99 |doi=10.3732/ajb.91.10.1683 |name-list-style=amp|issue=10 |pmid=21652317|doi-access=free }}</ref>

{{clade|style=line-height:100%; font-size:100%;
|label1=Living&nbsp;embryophytes
|1={{clade
   |1=Liverworts [[File:Conocephalum conicum (e, 144739-474742) 1022.jpg|50px]]
   |2={{clade
      |1=[[Biology:Moss|Moss]]es  [[File:WWB-0265-127-Polytrichum formosum.png|20px]]
      |2={{clade
         |1=[[Biology:Hornwort|Hornwort]]s [[File:Phaeoceros laevis 48205337 (white background).jpg|40px]]
         |label2=Tracheophytes
         |2={{clade
            |1=[[Biology:Lycophyte|Lycophyte]]s [[File:Lycopodium clavatum - Köhler–s Medizinal-Pflanzen-219 (extracted).jpg|50px]]
            |label2=[[Biology:Euphyllophyte|Euphyllophyte]]s
            |2={{clade
               |label1=[[Biology:Fern|Polypodiophytes]] |1=([[Biology:Fern|fern]]s and horsetails) [[File:California Arena Point fern.jpg|50px]]
               |label2=[[Biology:Spermatophyte|Spermatophyte]]s
               |2={{clade
                  |1=[[Biology:Gymnosperm|Gymnosperm]]s [[File:PIH 1830 Scots Pine (Pinus sylvestris) graft clone collection in Röykkä Finland.jpg|40px]]
                  |2=[[Biology:Angiosperm|Angiosperm]]s ([[Biology:Flowering plant|flowering plant]]s) [[File:160 Ranunculus repens.jpg|50px]]
                  }}
               }}
            }}
         }}
      }}
   }}
}}

An updated phylogeny of Embryophytes based on the work by Novíkov & Barabaš-Krasni 2015<ref>{{cite book | author=Novíkov & Barabaš-Krasni | year=2015 | title=Modern plant systematics | pages=685 | publisher=Liga-Pres| isbn=978-966-397-276-3 |doi=10.13140/RG.2.1.4745.6164}}</ref> and Hao and Xue 2013<ref name=HaoXue13>{{Citation |last1=Hao |first1=Shougang |last2=Xue |first2=Jinzhuang |date=2013 |title=The early Devonian Posongchong flora of Yunnan: a contribution to an understanding of the evolution and early diversification of vascular plants |location=Beijing |publisher=Science Press |isbn=978-7-03-036616-0 |url=https://www.researchgate.net/publication/269875285 |access-date=2019-10-25 |pages=366 |name-list-style=amp}}</ref> with plant taxon authors from Anderson, Anderson & Cleal 2007<ref>{{cite book | author=Anderson, Anderson & Cleal | year=2007 | title=Brief history of the gymnosperms: classification, biodiversity, phytogeography and ecology | journal=Strelitzia | volume=20 | pages=280 | publisher=SANBI| isbn=978-1-919976-39-6 }}</ref> and some additional clade names.<ref>{{Cite book|url=https://archive.org/details/treeoflifephylog0000leco |url-access=registration|page=[https://archive.org/details/treeoflifephylog0000leco/page/175 175]|quote=hemitracheophytes.|title=The Tree of Life: A Phylogenetic Classification |last1=Lecointre|first1=Guillaume|last2=Guyader|first2=Hervé Le|date=2006|publisher=Harvard University Press |isbn=9780674021839}}</ref> Puttick et al./Nishiyama et al are used for the basal clades.<ref name="Puttick-2018">{{Cite journal |last1=Puttick |first1=Mark N. |last2=Morris |first2=Jennifer L. |last3=Williams |first3=Tom A. |last4=Cox |first4=Cymon J. |last5=Edwards |first5=Dianne |last6=Kenrick |first6=Paul |last7=Pressel |first7=Silvia |last8=Wellman |first8=Charles H. |last9=Schneider |first9=Harald |date=2018 |title=The Interrelationships of Land Plants and the Nature of the Ancestral Embryophyte |journal=Current Biology |volume=28 |issue=5|pages=733–745.e2|doi=10.1016/j.cub.2018.01.063 |pmid=29456145|doi-access=free|hdl=1983/ad32d4da-6cb3-4ed6-add2-2415f81b46da |hdl-access=free }}</ref><ref>{{Cite journal |last1=Nishiyama |first1=Tomoaki |last2=Wolf|first2=Paul G. |last3=Kugita |first3=Masanori|last4=Sinclair |first4=Robert B. |last5=Sugita |first5=Mamoru |last6=Sugiura |first6=Chika |last7=Wakasugi |first7=Tatsuya |last8=Yamada|first8=Kyoji |last9=Yoshinaga |first9=Koichi |date=2004-10-01|title=Chloroplast Phylogeny Indicates that Bryophytes Are Monophyletic |journal=Molecular Biology and Evolution |volume=21 |issue=10 |pages=1813–1819 |doi=10.1093/molbev/msh203|pmid=15240838 |issn=0737-4038 |doi-access=free}}</ref><ref>{{Cite journal |last1=Gitzendanner |first1=Matthew A. |last2=Soltis |first2=Pamela S. |last3=Wong |first3=Gane K.-S. |last4=Ruhfel |first4=Brad R. |last5=Soltis |first5=Douglas E. |date=2018 |title=Plastid phylogenomic analysis of green plants: A billion years of evolutionary history |journal=American Journal of Botany |volume=105 |issue=3 |pages=291–301 |doi=10.1002/ajb2.1048 |pmid=29603143 |issn=0002-9122 |doi-access=free}}</ref>

{{barlabel|size=13
|at1=1.5|label1=Paratracheophytes|bar1=#b88
|at2=7|label2=Lycophytes|bar2=#aca
|cladogram=
{{clade| style=font-size:80%;line-height:80%
|label1='''Embryophytes'''
|1={{Clade
  |label1=[[Biology:Bryophyte|Bryophyta]]
  |1={{Clade
    |1=[[Biology:Anthocerotophyta|Anthocerotophytina]] (Hornworts)
    |label2=[[Biology:Setaphyta|Setaphyta]]
    |2={{clade
      |1=Bryophytina (Mosses)
      |2=[[Biology:Marchantiophyta|Marchantiophytina]] (Liverworts)
       }}
     }}
  |label2=[[Biology:Polysporangiophyte|Polysporangiomorpha]]
  |2={{Clade
    |1=†[[Biology:Horneophytopsida|Horneophytopsida]] [Protracheophytes]
    |label2=Tracheophytina
    |2={{Cladex
      |1=†[[Biology:Cooksonia|Cooksonia]]ceae|barbegin1=#b88
      |2={{cladex
        |1=†''[[Biology:Aglaophyton|Aglaophyton]]''|bar1=#b88
        |2={{cladex
          |1=†Rhyniopsida|bar1=#b88
          |2={{cladex
            |1=†''[[Biology:Catenalis|Catenalis]]''|bar1=#b88
            |2={{cladex
              |1=†''[[Biology:Aberlemnia|Aberlemnia]]''|bar1=#b88
              |2={{cladex
                |1=†[[Biology:Hsua|Hsua]]ceae|bar1=#b88
                |2={{cladex
                  |1=†[[Biology:Renalia|Renalia]]ceae|barend1=#b88
                  |label2=Eutracheophytes
                  |2={{clade
                    |1={{clade
                      |1=†''[[Biology:Adoketophyton|Adoketophyton]]''|barbegin1=#aca
                      |2=†?[[Biology:Barinophytopsida|Barinophytopsida]]|bar2=#aca
                      |3=†[[Biology:Zosterophyllopsida|Zosterophyllopsida]]|bar3=#aca
                       }}
                    |2={{clade
                      |label1=Microphylls
                      |1={{clade
                        |1=†''[[Biology:Hicklingia|Hicklingia]]''|bar1=#aca
                        |2={{clade
                          |1=†''[[Biology:Gumuia|Gumuia]]''|bar1=#aca
                          |2={{clade
                            |1=†''Nothia''|bar1=#aca
                            |2={{clade
                              |1=†''Zosterophyllum deciduum''|bar1=#aca
                              |2=[[Biology:Lycopodiopsida|Lycopodiopsida]] (Clubmosses, Spikemosses & Quillworts)|barend2=#aca
                               }}
                             }}
                           }}
                         }}
                      |2={{clade
                        |1=†''[[Biology:Yunia|Yunia]]''
                        |label2=[[Biology:Euphyllophyte|Euphyllophyte]]s
                        |2={{clade
                          |1=†''[[Biology:Eophyllophyton|Eophyllophyton]]''
                          |2={{clade
                            |1=†[[Biology:Trimerophytopsida|Trimerophytopsida]]
                            |label2=Megaphylls
                            |2={{clade
                              |label1=Moniliformopses
                              |1={{clade sequential
                                |1=†''[[Biology:Ibyka|Ibyka]]''
                                |2=†''Pauthecophyton''
                                |3=†[[Biology:Cladoxylopsida|Cladoxylopsida]]
                                |4=[[Biology:Polypodiopsida|Polypodiopsida]] (ferns)
                                 }}
                              |label2=Radiatopses
                              |2={{clade sequential
                                |1=†''[[Biology:Celatheca|Celatheca]]''
                                |2=†''[[Biology:Pertica|Pertica]]''
                                |label3=Lignophytes
                                |3={{clade
                                    |1=†[[Biology:Progymnosperm|Progymnosperm]]s<br/>(paraphyletic)
                                    |2=[[Biology:Spermatophyte|Spermatophyte]]s (seed plants)
                                   }}
                                 }}
                               }}
                             }}
                           }}
                         }}
                       }}
                     }}
                   }}
                 }}
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}

==Diversity==

===Non-vascular land plants ===
{{further|Biology:Alternation of generations}}

[[File:Barbula spadicea (Sporenkapseln) IMG 0434.JPG|thumb|Most bryophytes, such as these mosses, produce stalked sporophytes from which their spores are released.]]

The non-vascular land plants, namely the [[Biology:Moss|moss]]es (Bryophyta), [[Biology:Hornwort|hornwort]]s (Anthocerotophyta), and liverworts (Marchantiophyta), are relatively small plants, often confined to environments that are humid or at least seasonally moist. They are limited by their reliance on water needed to disperse their [[Biology:Gamete|gamete]]s; a few are truly aquatic. Most are tropical, but there are many arctic species. They may locally dominate the ground cover in [[Earth:Tundra|tundra]] and [[Biology:Arctic–alpine|Arctic–alpine]] habitats or the epiphyte flora in rain forest habitats. 

They are usually studied together because of their many similarities. All three groups share a [[Biology:Haploid|haploid]]-dominant ([[Biology:Gametophyte|gametophyte]]) life cycle and unbranched [[Biology:Sporophyte|sporophyte]]s (the plant's diploid structure). These traits appear to be common to all early diverging lineages of plants on the land. Their life-cycle is strongly dominated by the haploid gametophyte generation. The sporophyte remains small and dependent on the parent gametophyte for its entire brief life. All other living groups of land plants have a life cycle dominated by the diploid sporophyte generation. It is in the diploid sporophyte that vascular tissue develops. Although some mosses have quite complex water-conducting vessels, they lack true vascular tissue.

Like the vascular plants, they have differentiated stems, and although these are most often no more than a few centimeters tall, they provide mechanical support. Most have leaves, although these typically are one cell thick and lack veins. They lack true roots or any deep anchoring structures. Some species grow a filamentous network of horizontal stems,{{clarification needed|reason=this this paragraph is about roots, not stems, and what is the definition of a filamentous (root)/stem?|date=August 2023}} but these have a primary function of mechanical attachment rather than extraction of soil nutrients (Palaeos 2008).

===Rise of vascular plants===
[[Image:Rhynia reconstruction.svg|thumb|upright=0.5|Reconstruction of a plant of ''Rhynia'']]
During the [[Earth:Silurian|Silurian]] and [[Earth:Devonian|Devonian]] periods (around {{period span/brief|Silurian|Devonian|-1}}), plants evolved which possessed true vascular tissue, including cells with walls strengthened by lignin ([[Biology:Tracheid|tracheid]]s). Some extinct early plants appear to be between the grade of organization of bryophytes and that of true vascular plants (eutracheophytes). Genera such as ''[[Biology:Horneophyton|Horneophyton]]'' have water-conducting tissue more like that of mosses, but a different life-cycle in which the sporophyte is more developed than the gametophyte. Genera such as ''[[Biology:Rhynia|Rhynia]]'' have a similar life-cycle but have simple tracheids and so are a kind of vascular plant.{{Citation needed|date=March 2011}} It was assumed that the gametophyte dominant phase seen in bryophytes used to be the ancestral condition in terrestrial plants, and that the sporophyte dominant stage in vascular plants was a derived trait. However, the gametophyte and sporophyte stages were probably equally independent from each other, and that the mosses and vascular plants in that case are both derived, and have evolved in opposite directions.<ref>{{Cite journal|title=Sporophytes of polysporangiate land plants from the early Silurian period may have been photosynthetically autonomous|first1=Petr|last1=Štorch|first2=Viktor|last2=Žárský|first3=Jiří|last3=Bek|first4=Jiří|last4=Kvaček|first5=Milan|last5=Libertín|date=May 28, 2018|journal=Nature Plants|volume=4|issue=5|pages=269–271|doi=10.1038/s41477-018-0140-y|pmid=29725100|s2cid=19151297}}</ref>

During the Devonian period, vascular plants diversified and spread to many different land environments. In addition to vascular tissues which transport water throughout the body, tracheophytes have an outer layer or cuticle that resists [[Earth:Desiccation|drying out]]. The sporophyte is the dominant generation, and in modern species develops [[Biology:Leaf|leaves]], [[Biology:Plant stem|stems]] and [[Biology:Root|root]]s, while the gametophyte remains very small.

{{Clear}}

===Lycophytes and euphyllophytes===
[[File:Lycopodiella inundata 002.jpg|thumb|''Lycopodiella inundata'', a lycophyte]]
{{Main|Biology:Lycopodiophyta}}
All the vascular plants which disperse through spores were once thought to be related (and were often grouped as 'ferns and allies'). However, recent research suggests that leaves evolved quite separately in two different lineages. The lycophytes or lycopodiophytes – modern clubmosses, spikemosses and quillworts – make up less than 1% of living vascular plants. They have small leaves, often called 'microphylls' or 'lycophylls', which are borne all along the stems in the clubmosses and spikemosses, and which effectively grow from the base, via an intercalary [[Biology:Meristem|meristem]].<ref name="Pryer2004p1582">{{Citation |last1=Pryer |first1=K.M. |last2=Schuettpelz |first2=E. |last3=Wolf |first3=P.G. |last4=Schneider |first4=H. |last5=Smith |first5=A.R. |last6=Cranfill |first6=R. |name-list-style=amp |year=2004 |title=Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences |journal=American Journal of Botany |volume=91 |issue=10 |pages=1582–98 |doi=10.3732/ajb.91.10.1582 |pmid=21652310 }}, pp. 1582–3</ref> It is believed that microphylls evolved from outgrowths on stems, such as spines, which later acquired veins (vascular traces).<ref>{{Citation |last=Boyce |first=C.K. |year=2005 |editor-last=Holbrook |editor-first=N.M. |editor2-last=Zwieniecki |editor2-first=M.A. |contribution=The evolutionary history of roots and leaves |title=Vascular Transport in Plants |location=Burlington |publisher=Academic Press |isbn=978-0-12-088457-5 |name-list-style=amp|doi=10.1016/B978-012088457-5/50025-3 |pages=479–499}}</ref>

Although the living lycophytes are all relatively small and inconspicuous plants, more common in the moist tropics than in temperate regions, during the [[Earth:Carboniferous|Carboniferous]] period tree-like lycophytes (such as ''[[Biology:Lepidodendron|Lepidodendron]]'') formed huge forests that dominated the landscape.<ref>{{citation |doi=10.1130/G31182.1 |last1=Sahney |first1=S.|last2=Benton |first2=M.J. |last3=Falcon-Lang |first3=H.J. |year=2010 |title= Rainforest collapse triggered Pennsylvanian tetrapod diversification in Euramerica |journal=Geology |volume= 38 |pages= 1079–1082 |name-list-style=amp|issue=12 |bibcode = 2010Geo....38.1079S }}</ref>

The euphyllophytes, making up more than 99% of living vascular plant species, have large 'true' leaves (megaphylls), which effectively grow from the sides or the apex, via marginal or apical meristems.<ref name="Pryer2004p1582"/> One theory is that megaphylls evolved from three-dimensional branching systems by first '{{Not a typo|planation}}' – flattening to produce a two dimensional branched structure – and then 'webbing' – tissue growing out between the flattened branches.<ref>{{Citation |last1=Beerling |first1=D.J. |last2=Fleming |first2=A.J. |year=2007 |title=Zimmermann's telome theory of megaphyll leaf evolution: a molecular and cellular critique |journal=Current Opinion in Plant Biology |volume=10 |issue=1 |pages=4–12 |doi=10.1016/j.pbi.2006.11.006 |name-list-style=amp|pmid=17141552 }}</ref> Others have questioned whether megaphylls evolved in the same way in different groups.<ref>{{Citation |last=Tomescu |first=A. |year=2009 |title=Megaphylls, microphylls and the evolution of leaf development |journal=Trends in Plant Science |volume=14 |issue=1 |pages=5–12 |doi=10.1016/j.tplants.2008.10.008 |pmid=19070531 }}</ref>{{Clear}}

===Ferns and horsetails===
{{main|Biology:Fern}}
The ferns and horsetails (the Polypodiophyta) form a clade; they use spores as their main method of dispersal. Traditionally, whisk ferns and horsetails were historically treated as distinct from 'true' ferns.<ref name=Smith2006>{{cite journal |last1=Smith |first1=A.R. |last2=Pryer |first2=K.M. |last3=Schuettpelz |first3=E. |last4=Korall |first4=P. |last5=Schneider |first5=H. |last6=Wolf |first6=P.G. |year=2006 |title=A classification for extant ferns |journal=Taxon |volume=55 |issue=3 |pages=705–731 |url=http://www.pryerlab.net/publication/fichier749.pdf |access-date=2011-01-28 |doi=10.2307/25065646 |name-list-style=amp|url-status=dead |archive-url=https://web.archive.org/web/20080226232147/http://www.pryerlab.net/publication/fichier749.pdf |archive-date=2008-02-26 |jstor=25065646 }}</ref> Living whisk ferns and horsetails do not have the large leaves (megaphylls) which would be expected of euphyllophytes. This has probably resulted from reduction, as evidenced by early fossil horsetails, in which the leaves are broad with branching veins.<ref name=Rutishauser1999>{{cite journal |last=Rutishauser |first=R. |year=1999 |title=Polymerous Leaf Whorls in Vascular Plants: Developmental Morphology and Fuzziness of Organ Identities |journal=International Journal of Plant Sciences |volume=160 |issue=6 |pages=81–103 |doi=10.1086/314221 |pmid=10572024|s2cid=4658142 }}</ref>

Ferns are a large and diverse group, with some 12,000 [[Biology:Species|species]].<ref name="chapman">{{cite web |last=Chapman |first=Arthur D. |year=2009 |title=Numbers of Living Species in Australia and the World. Report for the Australian Biological Resources Study |location=Canberra, Australia |url=http://www.environment.gov.au/biodiversity/abrs/publications/other/species-numbers/index.html |access-date=2011-03-11 }}</ref> A stereotypical fern has broad, much divided leaves, which grow by unrolling.

===Seed plants===
{{main|Biology:Spermatophyte}}

[[File:Autumn Conker - geograph.org.uk - 370125.jpg|thumb|Large seed of [[Biology:Aesculus|horse chestnut]], ''Aesculus hippocastanum'']]

Seed plants, which first appeared in the fossil record towards the end of the [[Earth:Paleozoic|Paleozoic]] era, reproduce using [[Earth:Desiccation|desiccation]]-resistant capsules called [[Biology:Seed|seed]]s. Starting from a plant which disperses by spores, highly complex changes are needed to produce seeds. The sporophyte has two kinds of spore-forming organs or sporangia. One kind, the megasporangium, produces only a single large spore, a megaspore. This sporangium is surrounded by sheathing layers or integuments which form the seed coat. Within the seed coat, the megaspore develops into a tiny gametophyte, which in turn produces one or more egg cells. Before fertilization, the sporangium and its contents plus its coat is called an ovule; after fertilization a seed. In parallel to these developments, the other kind of sporangium, the microsporangium, produces microspores. A tiny gametophyte develops inside the wall of a microspore, producing a [[Biology:Pollen|pollen]] grain. Pollen grains can be physically transferred between plants by the [[Earth:Wind|wind]] or animals, most commonly [[Biology:Insect|insect]]s. Pollen grains can also transfer to an ovule of the same plant, either with the same flower or between two flowers of the same plant (self-fertilization). When a pollen grain reaches an ovule, it enters via a microscopic gap in the coat, the micropyle. The tiny gametophyte inside the pollen grain then produces sperm cells which move to the egg cell and fertilize it.<ref>{{Citation |last1=Taylor |first1=T.N. |last2=Taylor |first2=E.L. |last3=Krings |first3=M. |year=2009 |title=Paleobotany, The Biology and Evolution of Fossil Plants |edition=2nd |location=Amsterdam; Boston |publisher=Academic Press |isbn=978-0-12-373972-8 |pages=508ff}}</ref> Seed plants include two clades with living members, the [[Biology:Gymnosperm|gymnosperm]]s and the [[Biology:Angiosperm|angiosperm]]s or flowering plants. In gymnosperms, the ovules or seeds are not further enclosed. In angiosperms, they are enclosed within the carpel. Angiosperms typically also have other, secondary structures, such as petals, which together form a [[Biology:Flower|flower]].

==References==
{{Reflist|30em}}

==Bibliography==
* {{Citation |last1=Raven |first1=P.H. |last2=Evert |first2=R.F. |last3=Eichhorn |first3=S.E. |year=2005 |title=Biology of Plants |edition=7th |location=New York |publisher=W.H. Freeman |isbn=978-0-7167-1007-3 |name-list-style=amp}}
* {{Citation |last1=Stewart |first1=W.N. |last2=Rothwell |first2=G.W. |year=1993 |title=Paleobotany and the Evolution of Plants |edition=2nd |location=Cambridge |publisher=Cambridge University Press |isbn=978-0-521-38294-6 |name-list-style=amp}}
* {{Citation |last1=Taylor |first1=T.N. |last2=Taylor |first2=E.L. |last3=Krings |first3=M. |year=2009 |title=Paleobotany, The Biology and Evolution of Fossil Plants |edition=2nd |location=Amsterdam; Boston |publisher=Academic Press |isbn=978-0-12-373972-8 |name-list-style=amp}}

{{Botany}}
{{Plant classification}}

{{Taxonbar|from=Q192154}}

[[Category:Plants]]
[[Category:Dapingian first appearances]]
[[Category:Extant Ordovician first appearances]]

{{Sourceattribution|Embryophyte}}