APG IV system
The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was published in 2016, seven years after its predecessor the APG III system was published in 2009, and 18 years after the first APG system was published in 1998. In 2009, a linear arrangement of the system was published separately; the APG IV paper includes such an arrangement, cross-referenced to the 2009 one.
Compared to the APG III system, the APG IV system recognizes five new orders (Boraginales, Dilleniales, Icacinales, Metteniusales and Vahliales), along with some new families, making a total of 64 angiosperm orders and 416 families. In general, the authors describe their philosophy as "conservative", based on making changes from APG III only where "a well-supported need" has been demonstrated. This has sometimes resulted in placements that are not compatible with published studies, but where further research is needed before the classification can be changed.
Short version
Detailed version
Key to symbols used:
- * = the family has been added or its circumscription changed since the APG III system of 2009
- † = the order has been added since the APG III system
Independent lineage: unplaced to more inclusive clade
- Acorales Mart.
- Alismatales R.Br. ex Bercht. & J.Presl
- Araceae Juss., nom. cons.
- Tofieldiaceae Takht.
- Alismataceae Vent., nom. cons.
- Butomaceae Mirb., nom. cons.
- Hydrocharitaceae Juss., nom. cons.
- Scheuchzeriaceae F.Rudolphi, nom. cons.
- Aponogetonaceae Planch., nom. cons.
- Juncaginaceae Rich., nom. cons. *
- Maundiaceae Nakai *
- Zosteraceae Dumort., nom. cons.
- Potamogetonaceae Bercht. & J.Presl, nom. cons
- Posidoniaceae Vines, nom. cons.
- Ruppiaceae Horan., nom. cons.
- Cymodoceaceae Vines, nom. cons.
- Petrosaviales Takht.
- Dioscoreales Mart.
- Pandanales R.Br. ex Bercht. & J.Presl
- Liliales Perleb
- Asparagales Link
- Arecales Bromhead
- Commelinales Mirb. ex Bercht. & J.Presl
- Zingiberales Griseb.
- Poales Small
- Typhaceae Juss., nom. cons.
- Bromeliaceae Juss., nom. cons.
- Rapateaceae Dumort., nom. cons.
- Xyridaceae C.Agardh, nom. cons.
- Eriocaulaceae Martinov, nom. cons.
- Mayacaceae Kunth, nom. cons.
- Thurniaceae Engl., nom. cons.
- Juncaceae Juss., nom. cons.
- Cyperaceae Juss., nom. cons.
- Restionaceae R.Br., nom. cons. * (including Anarthriaceae D.W.Cutler & Airy Shaw, Centrolepidaceae Endl., nom. cons.)
- Flagellariaceae Dumort., nom. cons.
- Joinvilleaceae Toml. & A.C.Sm.
- Ecdeiocoleaceae D.W.Cutler & Airy Shaw
- Poaceae Barnhart, nom. cons. (= Gramineae Juss., nom. cons.)
Probable sister of eudicots
- Saxifragales Bercht. & J.Presl
- Peridiscaceae Kuhlm., nom. cons.
- Paeoniaceae Raf., nom. cons.
- Altingiaceae Lindl., nom. cons.
- Hamamelidaceae R.Br., nom. cons.
- Cercidiphyllaceae Engl., nom. cons.
- Daphniphyllaceae Mu€ll.Arg., nom. cons.
- Iteaceae J.Agardh, nom. cons.
- Grossulariaceae DC., nom. cons.
- Saxifragaceae Juss., nom. cons.
- Crassulaceae J.St.-Hil., nom. cons.
- Aphanopetalaceae Doweld
- Tetracarpaeaceae Nakai
- Penthoraceae Rydb. ex Britton, nom. cons.
- Haloragaceae R.Br., nom. cons.
- Cynomoriaceae Endl. ex Lindl., nom. cons.
COM clade; placement uncertain
- Celastrales Link
- Oxalidales Bercht. & J.Presl
- Malpighiales Juss. ex Bercht. & J.Presl
- Pandaceae Engl. & Gilg, nom. cons.
- Irvingiaceae Exell & Mendonc"a, nom. cons. * (including Allantospermum Forman)
- Ctenolophonaceae Exell & Mendonc"a
- Rhizophoraceae Pers., nom. cons.
- Erythroxylaceae Kunth, nom. cons.
- Ochnaceae DC., nom. cons.
- Bonnetiaceae L.Beauvis. ex Nakai
- Clusiaceae Lindl., nom. cons. (= Guttiferae Juss., nom. cons.)
- Calophyllaceae J.Agardh
- Podostemaceae Rich. ex Kunth, nom. cons.
- Hypericaceae Juss., nom. cons.
- Caryocaraceae Voigt, nom. cons.
- Lophopyxidaceae H.Pfeiff.
- Putranjivaceae Meisn.
- Centroplacaceae Doweld & Reveal
- Elatinaceae Dumort., nom. cons.
- Malpighiaceae Juss., nom. cons.
- Balanopaceae Benth. & Hook.f., nom. cons.
- Trigoniaceae A.Juss., nom. cons.
- Dichapetalaceae Baill., nom. cons.
- Euphroniaceae Marc.-Berti
- Chrysobalanaceae R.Br., nom. cons.
- Humiriaceae A.Juss., nom. cons.
- Achariaceae Harms, nom. cons.
- Violaceae Batsch, nom. cons.
- Goupiaceae Miers
- Passifloraceae Juss. ex Roussel, nom. cons.
- Lacistemataceae Mart., nom. cons.
- Salicaceae Mirb., nom. cons.
- Peraceae Klotzsch *
- Rafflesiaceae Dumort., nom. cons.
- Euphorbiaceae Juss., nom. cons. *
- Linaceae DC. ex Perleb, nom. cons.
- Ixonanthaceae Planch. ex Miq., nom. cons. *
- Picrodendraceae Small, nom. cons.
- Phyllanthaceae Martinov, nom. cons.
Rosids continued
- Geraniales Juss. ex Bercht. & J.Presl
- Geraniaceae Juss., nom. cons.
- Francoaceae A.Juss., nom. cons. * (including Bersamaceae Doweld, Greyiaceae Hutch., nom. cons., Ledocarpaceae Meyen, Melianthaceae Horan., nom. cons., Rhynchothecaceae A.Juss., Vivianiaceae Klotzsch, nom. cons.)
- Myrtales Juss. ex Bercht. & J.Presl
- Crossosomatales Takht. ex Reveal
- Picramniales Doweld
- Huerteales Doweld
- Sapindales Juss. ex Bercht. & J.Presl
- Malvales Juss. ex Bercht. & J.Presl
- Brassicales Bromhead
- Akaniaceae Stapf, nom. cons.
- Tropaeolaceae Juss. ex DC., nom. cons.
- Moringaceae Martinov, nom. cons.
- Caricaceae Dumort., nom. cons.
- Limnanthaceae R.Br., nom. cons.
- Setchellanthaceae Iltis
- Koeberliniaceae Engl., nom. cons.
- Bataceae Mart. ex Perleb, nom. cons.
- Salvadoraceae Lindl., nom. cons.
- Emblingiaceae Airy Shaw
- Tovariaceae Pax, nom. cons.
- Pentadiplandraceae Hutch. & Dalziel
- Gyrostemonaceae A.Juss., nom. cons.
- Resedaceae Martinov, nom. cons. * (including Borthwickiaceae J.X.Su et al., Stixidaceae Doweld as 'Stixaceae', Forchhammeria Liebm.)
- Capparaceae Juss., nom. cons. *
- Cleomaceae Bercht. & J.Presl
- Brassicaceae Burnett, nom. cons. (= Cruciferae Juss., nom. cons.)
Superasterids
- Berberidopsidales Doweld
- Santalales R.Br. ex Bercht. & J.Presl
- Olacaceae R.Br., nom. cons. (not monophyletic; including Aptandraceae Miers, Coulaceae Tiegh., Erythropalaceae Planch. ex Miq., nom. cons., Octoknemaceae Soler. nom. cons., Strombosiaceae Tiegh., Ximeniaceae Horan.)
- Opiliaceae Valeton, nom. cons.
- Balanophoraceae Rich., nom. cons.
- Santalaceae R.Br., nom. cons. (not monophyletic if Balanophoraceae are embedded; including Amphorogynaceae Nickrent & Der, Cervantesiaceae Nickrent & Der, Comandraceae Nickrent & Der, Nanodeaceae Nickrent & Der, Thesiaceae Vest, Viscaceae Batsch)
- Misodendraceae J.Agardh, nom. cons.
- Schoepfiaceae Blume
- Loranthaceae Juss., nom. cons.
- Caryophyllales Juss. ex Bercht. & J.Presl
- Frankeniaceae Desv., nom. cons.
- Tamaricaceae Link, nom. cons.
- Plumbaginaceae Juss., nom. cons.
- Polygonaceae Juss., nom. cons.
- Droseraceae Salisb., nom. cons.
- Nepenthaceae Dumort, nom. cons.
- Drosophyllaceae Chrtek et al.
- Dioncophyllaceae Airy Shaw, nom. cons.
- Ancistrocladaceae Planch. ex Walp., nom. cons.
- Rhabdodendraceae Prance
- Simmondsiaceae Tiegh.
- Physenaceae Takht.
- Asteropeiaceae Takht. ex Reveal & Hoogland
- Macarthuriaceae Christenh. *
- Microteaceae Schäferhoff & Borsch *
- Caryophyllaceae Juss., nom. cons.
- Achatocarpaceae Heimerl, nom. cons.
- Amaranthaceae Juss., nom. cons.
- Stegnospermataceae Nakai
- Limeaceae Shipunov ex Reveal *
- Lophiocarpaceae Doweld & Reveal
- Kewaceae Christenh. *
- Barbeuiaceae Nakai
- Gisekiaceae Nakai
- Aizoaceae Martinov, nom. cons.
- Phytolaccaceae R.Br., nom. cons. *
- Petiveriaceae C.Agardh * (including Rivinaceae C.Agardh)
- Sarcobataceae Behnke
- Nyctaginaceae Juss., nom. cons.
- Molluginaceae Bartl., nom. cons. *
- Montiaceae Raf.
- Didiereaceae Radlk., nom. cons.
- Basellaceae Raf., nom. cons.
- Halophytaceae S.Soriano
- Talinaceae Doweld
- Portulacaceae Juss., nom. cons.
- Anacampserotaceae Eggli & Nyffeler
- Cactaceae Juss., nom. cons.
- Cornales Link
- Ericales Bercht. & J.Presl
- Balsaminaceae A.Rich., nom. cons.
- Marcgraviaceae Bercht. & J.Presl, nom. cons.
- Tetrameristaceae Hutch.
- Fouquieriaceae DC., nom. cons.
- Polemoniaceae Juss., nom. cons.
- Lecythidaceae A.Rich., nom. cons.
- Sladeniaceae Airy Shaw
- Pentaphylacaceae Engl., nom. cons.
- Sapotaceae Juss., nom. cons.
- Ebenaceae Gu€rke, nom. cons.
- Primulaceae Batsch ex Borkh., nom. cons.
- Theaceae Mirb., nom. cons.
- Symplocaceae Desf., nom. cons.
- Diapensiaceae Lindl., nom. cons.
- Styracaceae DC. & Spreng., nom. cons.
- Sarraceniaceae Dumort., nom. cons.
- Roridulaceae Martinov, nom. cons.
- Actinidiaceae Gilg & Werderm., nom. cons.
- Clethraceae Klotzsch, nom. cons.
- Cyrillaceae Lindl., nom. cons.
- Ericaceae Juss., nom. cons.
- Mitrastemonaceae Makino, nom. cons. (placement in order unclear)
- Icacinales Tiegh. †
- Metteniusales Takht. †
- Garryales Mart.
- Gentianales Juss. ex Bercht. & J.Presl
- Boraginales Juss. ex Bercht. & J.Presl †
- Boraginaceae Juss., nom. cons. (including Codonaceae Weigend & Hilger)
- Vahliales Doweld †
- Solanales Juss. ex Bercht. & J.Presl
- Lamiales Bromhead
- Plocospermataceae Hutch.
- Carlemanniaceae Airy Shaw
- Oleaceae Hoffmanns. & Link, nom. cons.
- Tetrachondraceae Wettst.
- Calceolariaceae Olmstead
- Gesneriaceae Rich. & Juss., nom. cons. * (the position of Peltanthera Benth. is problematic and here considered unplaced to family)
- Plantaginaceae Juss., nom. cons.
- Scrophulariaceae Juss., nom. cons.
- Stilbaceae Kunth, nom. cons.
- Linderniaceae Borsch et al.
- Byblidaceae Domin, nom. cons.
- Martyniaceae Horan., nom. cons.
- Pedaliaceae R.Br., nom. cons.
- Acanthaceae Juss., nom. cons.
- Bignoniaceae Juss., nom. cons.
- Lentibulariaceae Rich., nom. cons.
- Schlegeliaceae Reveal
- Thomandersiaceae Sreem.
- Verbenaceae J.St.Hil., nom. cons.
- Lamiaceae Martinov, nom. cons. (= Labiatae Juss., nom. cons.)
- Mazaceae Reveal
- Phrymaceae Schauer, nom. cons. *
- Paulowniaceae Nakai
- Orobanchaceae Vent., nom. cons. * (including Lindenbergiaceae Doweld, Rehmanniaceae Reveal)
- Aquifoliales Senft
- Asterales Link
- Escalloniales Link
- Bruniales Dumort.
- Paracryphiales Takht. ex Reveal
- Dipsacales Juss. ex Bercht. & J.Presl
- Apiales Nakai
Phylogeny
Like the earlier APG systems, the APG IV revision is based on a phylogenetic tree for the angiosperms, as shown below.
References
Bibliography
- Angiosperm Phylogeny Group (2009), "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III", Botanical Journal of the Linnean Society, 161 (2): 105–121, doi:10.1111/j.1095-8339.2009.00996.x, retrieved 2010-12-10
- Angiosperm Phylogeny Group (2016), "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV" (PDF), Botanical Journal of the Linnean Society, 181 (1): 1–20, doi:10.1111/boj.12385, retrieved 2016-06-11
- Haston, E.; Richardson, J.E.; Stevens, P.F.; Chase, M.W. & Harris, D.J. (2009), "The Linear Angiosperm Phylogeny Group (LAPG) III: a linear sequence of the families in APG III" (PDF), Botanical Journal of the Linnean Society, 161: 128–131, doi:10.1111/j.1095-8339.2009.01000.x, retrieved 2016-06-13
- Fay, Michael (9 May 2016), "APG - classification by consensus", Kew Science, RBG Kew, retrieved 2016-06-12
- Cole, Theodor C.H. & Hilger, Hartmut H. (April 2016), Angiosperm Phylogeny Poster - Flowering Plant Systematics (PDF), retrieved 2016-06-12