APG system explained

The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved APG II in 2003, APG III system in 2009 and APG IV system in 2016.

History

The original APG system is unusual in being based, not on total evidence, but on the cladistic analysis of the DNA sequences of three genes, two chloroplast genes and one gene coding for ribosomes. Although based on molecular evidence only, its constituent groups prove to be supported by other evidence as well, for example pollen morphology supports the split between the eudicots and the rest of the former dicotyledons.

The system is rather controversial in its decisions at the family level, splitting a number of long-established families and submerging some other families. It also is unusual in not using botanical names above the level of order, that is, an order is the highest rank that will have a formal botanical name in this system. Higher groups are defined only as clades, with names such as monocots, eudicots, rosids, asterids.

The APG system was superseded in 2003 by a revision, the APG II system, in 2009 by a next revision, the APG III system, and then in 2016 by a further revision, the APG IV system.

Groups

The main groups in the system (all unranked clades) are:

monocots

commelinoids

eudicots

core eudicots

rosids

eurosids I

eurosids II

asterids

euasterids I

euasterids II

The APG system recognises 462 families and 40 orders: these are assigned as follows. In the beginning of each listing some families or orders that are not placed in a further clade:

family Amborellaceae

family Austrobaileyaceae

family Canellaceae

family Chloranthaceae

family Hydnoraceae

family Illiciaceae

family Nymphaeaceae [+ family [[Cabombaceae]]]

family Rafflesiaceae

family Schisandraceae

family Trimeniaceae

family Winteraceae

order Ceratophyllales

family Ceratophyllaceae

order Laurales

family Atherospermataceae

family Calycanthaceae

family Gomortegaceae

family Hernandiaceae

family Lauraceae

family Monimiaceae

family Siparunaceae

order Magnoliales

family Annonaceae

family Degeneriaceae

family Eupomatiaceae

family Himantandraceae

family Magnoliaceae

family Myristicaceae

order Piperales

family Aristolochiaceae

family Lactoridaceae

family Piperaceae

family Saururaceae

clade monocots

family Corsiaceae

family Japonoliriaceae

family Nartheciaceae

family Petrosaviaceae

family Triuridaceae

order Acorales

family Acoraceae

order Alismatales

family Alismataceae

family Aponogetonaceae

family Araceae

family Butomaceae

family Cymodoceaceae

family Hydrocharitaceae

family Juncaginaceae

family Limnocharitaceae

family Posidoniaceae

family Potamogetonaceae

family Ruppiaceae

family Scheuchzeriaceae

family Tofieldiaceae

family Zosteraceae

order Asparagales

family Agapanthaceae

family Agavaceae

family Alliaceae

family Amaryllidaceae

family Anemarrhenaceae

family Anthericaceae

family Aphyllanthaceae

family Asparagaceae

family Asphodelaceae

family Asteliaceae

family Behniaceae

family Blandfordiaceae

family Boryaceae

family Convallariaceae

family Doryanthaceae

family Hemerocallidaceae

family Herreriaceae

family Hesperocallidaceae

family Hyacinthaceae

family Hypoxidaceae

family Iridaceae

family Ixioliriaceae

family Lanariaceae

family Laxmanniaceae

family Orchidaceae

family Tecophilaeaceae

family Themidaceae

family Xanthorrhoeaceae

family Xeronemataceae

order Dioscoreales

family Burmanniaceae

family Dioscoreaceae

family Taccaceae

family Thismiaceae

family Trichopodaceae

order Liliales

family Alstroemeriaceae

family Campynemataceae

family Colchicaceae

family Liliaceae

family Luzuriagaceae

family Melanthiaceae

family Philesiaceae

family Ripogonaceae

family Smilacaceae

order Pandanales

family Cyclanthaceae

family Pandanaceae

family Stemonaceae

family Velloziaceae

clade commelinoids

family Abolbodaceae

family Bromeliaceae

family Dasypogonaceae

family Hanguanaceae

family Mayacaceae

family Rapateaceae

order Arecales

family Arecaceae

order Commelinales

family Commelinaceae

family Haemodoraceae

family Philydraceae

family Pontederiaceae

order Poales

family Anarthriaceae

family Centrolepidaceae

family Cyperaceae

family Ecdeiocoleaceae

family Eriocaulaceae

family Flagellariaceae

family Hydatellaceae

family Joinvilleaceae

family Juncaceae

family Poaceae

family Prioniaceae

family Restionaceae

family Sparganiaceae

family Thurniaceae

family Typhaceae

family Xyridaceae

order Zingiberales

family Cannaceae

family Costaceae

family Heliconiaceae

family Lowiaceae

family Marantaceae

family Musaceae

family Strelitziaceae

family Zingiberaceae

clade eudicots

family Buxaceae

family Didymelaceae

family Sabiaceae

family Trochodendraceae [+ family [[Tetracentraceae]]]

order Proteales

family Nelumbonaceae

family Platanaceae

family Proteaceae

order Ranunculales

family Berberidaceae

family Circaeasteraceae [+ family [[Kingdoniaceae]]]

family Eupteleaceae

family Lardizabalaceae

family Menispermaceae

family Papaveraceae [+ family [[Fumariaceae]] and family Pteridophyllaceae]

family Ranunculaceae

clade core eudicots

family Aextoxicaceae

family Berberidopsidaceae

family Dilleniaceae

family Gunneraceae

family Myrothamnaceae

family Vitaceae

order Caryophyllales

family Achatocarpaceae

family Aizoaceae

family Amaranthaceae

family Ancistrocladaceae

family Asteropeiaceae

family Basellaceae

family Cactaceae

family Caryophyllaceae

family Didiereaceae

family Dioncophyllaceae

family Droseraceae

family Drosophyllaceae

family Frankeniaceae

family Molluginaceae

family Nepenthaceae

family Nyctaginaceae

family Physenaceae

family Phytolaccaceae

family Plumbaginaceae

family Polygonaceae

family Portulacaceae

family Rhabdodendraceae

family Sarcobataceae

family Simmondsiaceae

family Stegnospermataceae

family Tamaricaceae

order Santalales

family Olacaceae

family Opiliaceae

family Loranthaceae

family Misodendraceae

family Santalaceae

order Saxifragales

family Altingiaceae

family Cercidiphyllaceae

family Crassulaceae

family Daphniphyllaceae

family Grossulariaceae

family Haloragaceae

family Hamamelidaceae

family Iteaceae

family Paeoniaceae

family Penthoraceae

family Pterostemonaceae

family Saxifragaceae

family Tetracarpaeaceae

clade rosids

family Aphloiaceae

family Crossosomataceae

family Ixerbaceae

family Krameriaceae

family Picramniaceae

family Podostemaceae

family Stachyuraceae

family Staphyleaceae

family Tristichaceae

family Zygophyllaceae

order Geraniales

family Francoaceae

family Geraniaceae [+ family [[Hypseocharitaceae]]]

family Greyiaceae

family Ledocarpaceae

family Melianthaceae

family Vivianiaceae

clade eurosids I

family Celastraceae

family Huaceae

family Parnassiaceae [+ family [[Lepuropetalaceae]]]

family Stackhousiaceae

order Cucurbitales

family Anisophylleaceae

family Begoniaceae

family Coriariaceae

family Corynocarpaceae

family Cucurbitaceae

family Datiscaceae

family Tetramelaceae

order Fabales

family Fabaceae

family Polygalaceae

family Quillajaceae

family Surianaceae

order Fagales

family Betulaceae

family Casuarinaceae

family Fagaceae

family Juglandaceae

family Myricaceae

family Nothofagaceae

family Rhoipteleaceae

family Ticodendraceae

order Malpighiales

family Achariaceae

family Balanopaceae

family Caryocaraceae

family Chrysobalanaceae

family Clusiaceae

family Dichapetalaceae

family Erythroxylaceae

family Euphorbiaceae

family Euphroniaceae

family Flacourtiaceae

family Goupiaceae

family Hugoniaceae

family Humiriaceae

family Irvingiaceae

family Ixonanthaceae

family Lacistemaceae

family Linaceae

family Malesherbiaceae

family Malpighiaceae

family Medusagynaceae

family Ochnaceae

family Pandaceae

family Passifloraceae

family Putranjivaceae

family Quiinaceae

family Rhizophoraceae

family Salicaceae

family Scyphostegiaceae

family Trigoniaceae

family Turneraceae

family Violaceae

order Oxalidales

family Cephalotaceae

family Connaraceae

family Cunoniaceae

family Elaeocarpaceae

family Oxalidaceae

family Tremandraceae

order Rosales

family Barbeyaceae

family Cannabaceae

family Cecropiaceae

family Celtidaceae

family Dirachmaceae

family Elaeagnaceae

family Moraceae

family Rhamnaceae

family Rosaceae

family Ulmaceae

family Urticaceae

clade eurosids II

family Tapisciaceae

order Brassicales

family Akaniaceae [+ family [[Bretschneideraceae]]]

family Bataceae

family Brassicaceae

family Caricaceae

family Emblingiaceae

family Gyrostemonaceae

family Koeberliniaceae

family Limnanthaceae

family Moringaceae

family Pentadiplandraceae

family Resedaceae

family Salvadoraceae

family Setchellanthaceae

family Tovariaceae

family Tropaeolaceae

order Malvales

family Bixaceae [+ family [[Diegodendraceae]]]

family Cistaceae

family Cochlospermaceae

family Dipterocarpaceae

family Malvaceae

family Muntingiaceae

family Neuradaceae

family Sarcolaenaceae

family Sphaerosepalaceae

family Thymelaeaceae

order Myrtales

family Alzateaceae

family Combretaceae

family Crypteroniaceae

family Heteropyxidaceae

family Lythraceae

family Melastomataceae

family Memecylaceae

family Myrtaceae

family Oliniaceae

family Onagraceae

family Penaeaceae

family Psiloxylaceae

family Rhynchocalycaceae

family Vochysiaceae

order Sapindales

family Anacardiaceae

family Biebersteiniaceae

family Burseraceae

family Kirkiaceae

family Meliaceae

family Nitrariaceae [+ family [[Peganaceae]]]

family Rutaceae

family Sapindaceae

family Simaroubaceae

clade asterids

order Cornales

family Cornaceae [+ family [[Nyssaceae]]]

family Grubbiaceae

family Hydrangeaceae

family Hydrostachyaceae

family Loasaceae

order Ericales

family Actinidiaceae

family Balsaminaceae

family Clethraceae

family Cyrillaceae

family Diapensiaceae

family Ebenaceae

family Ericaceae

family Fouquieriaceae

family Halesiaceae

family Lecythidaceae

family Marcgraviaceae

family Myrsinaceae

family Pellicieraceae

family Polemoniaceae

family Primulaceae

family Roridulaceae

family Sapotaceae

family Sarraceniaceae

family Styracaceae

family Symplocaceae

family Ternstroemiaceae

family Tetrameristaceae

family Theaceae

family Theophrastaceae

clade euasterids I

family Boraginaceae

family Plocospermataceae

family Vahliaceae

order Garryales

family Aucubaceae

family Eucommiaceae

family Garryaceae

family Oncothecaceae

order Gentianales

family Apocynaceae

family Gelsemiaceae

family Gentianaceae

family Loganiaceae

family Rubiaceae

order Lamiales

family Acanthaceae

family Avicenniaceae

family Bignoniaceae

family Buddlejaceae

family Byblidaceae

family Cyclocheilaceae

family Gesneriaceae

family Lamiaceae

family Lentibulariaceae

family Myoporaceae

family Oleaceae

family Orobanchaceae

family Paulowniaceae

family Pedaliaceae [+ family [[Martyniaceae]]]

family Phrymaceae

family Plantaginaceae

family Schlegeliaceae

family Scrophulariaceae

family Stilbaceae

family Tetrachondraceae

family Verbenaceae

order Solanales

family Convolvulaceae

family Hydroleaceae

family Montiniaceae

family Solanaceae

family Sphenocleaceae

clade euasterids II

family Adoxaceae

family Bruniaceae

family Carlemanniaceae

family Columelliaceae [+ family [[Desfontainiaceae]]]

family Eremosynaceae

family Escalloniaceae

family Icacinaceae

family Polyosmaceae

family Sphenostemonaceae

family Tribelaceae

order Apiales

family Apiaceae

family Araliaceae

family Aralidiaceae

family Griseliniaceae

family Melanophyllaceae

family Pittosporaceae

family Torricelliaceae

order Aquifoliales

family Aquifoliaceae

family Helwingiaceae

family Phyllonomaceae

order Asterales

family Alseuosmiaceae

family Argophyllaceae

family Asteraceae

family Calyceraceae

family Campanulaceae [+ family [[Lobeliaceae]]]

family Carpodetaceae

family Donatiaceae

family Goodeniaceae

family Menyanthaceae

family Pentaphragmataceae

family Phellinaceae

family Rousseaceae

family Stylidiaceae

order Dipsacales

family Caprifoliaceae

family Diervillaceae

family Dipsacaceae

family Linnaeaceae

family Morinaceae

family Valerianaceae

Note: "+ ..." = optional seggregrate family, that may be split off from the preceding family.

family Balanophoraceae

family Bonnetiaceae

family Cardiopteridaceae

family Ctenolophonaceae

family Cynomoriaceae

family Cytinaceae

family Dipentodontaceae

family Elatinaceae

family Geissolomataceae

family Hoplestigmataceae

family Kaliphoraceae

family Lepidobotryaceae

family Lissocarpaceae

family Lophopyxidaceae

family Medusandraceae

family Metteniusaceae

family Mitrastemonaceae

family Paracryphiaceae

family Pentaphylacaceae

family Peridiscaceae

family Plagiopteraceae

family Pottingeriaceae

family Sladeniaceae

family Strasburgeriaceae

family Tepuianthaceae

See also

References

External links