See also: Angiosperm Phylogeny Group.
The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group.[1] It was a revision of the first APG system, published in 1998, and was superseded in 2009 by a further revision, the APG III system.
APG II was published as:
Each of the APG systems represents the broad consensus of a number of systematic botanists, united in the APG, working at several institutions worldwide.
The APG II system recognized 45 orders, five more than the APG system. The new orders were Austrobaileyales, Canellales, Gunnerales, Celastrales, and Crossosomatales, all of which were families unplaced as to order, although contained in supra-ordinal clades, in the APG system. APG II recognized 457 families, five fewer than the APG system. Thirty-nine of the APG II families were not placed in any order, but 36 of the 39 were placed in a supra-ordinal clade within the angiosperms. Fifty-five of the families came to be known as "bracketed families". They were optional segregates of families that could be circumscribed in a larger sense.
The APG II system was influential and was adopted in whole or in part (sometimes with modifications) in a number of references. It was superseded 6½ years later by the APG III system, published in October 2009.
Main groups in the system (all unranked clades between the ranks of class and order):
monocots
core eudicots
Shown below is the classification in full detail, except for the fifteen genera and three families that were unplaced in APG II. The unplaced taxa were listed at the end of the appendix in a section entitled "Taxa of Uncertain Position". Under some of the clades are listed the families that were placed incertae sedis in that clade. Thirty-six families were so placed. This means that their relationship to other members of the clade is not known.
family Amborellaceae
family Chloranthaceae
family Nymphaeaceae [+ family [[Cabombaceae]]]
order Austrobaileyales
order Ceratophyllales
clade magnoliids
order Canellales
order Laurales
order Magnoliales
order Piperales
clade monocots
family Petrosaviaceae
order Acorales
order Alismatales
order Asparagales
order Dioscoreales
order Liliales
order Pandanales
clade commelinids
family Dasypogonaceae
order Arecales
order Commelinales
order Poales
order Zingiberales
clade eudicots
family Buxaceae [+ family [[Didymelaceae]]]
family Sabiaceae
family Trochodendraceae [+ family [[Tetracentraceae]]]
order Proteales
order Ranunculales
clade core eudicots
family Aextoxicaceae
family Berberidopsidaceae
family Dilleniaceae
order Gunnerales
order Caryophyllales
order Santalales
order Saxifragales
clade rosids
family Aphloiaceae
family Geissolomataceae
family Ixerbaceae
family Picramniaceae
family Strasburgeriaceae
family Vitaceae
order Crossosomatales
order Geraniales
order Myrtales
clade eurosids I
family Zygophyllaceae [+ family [[Krameriaceae]]]
family Huaceae
order Celastrales
order Cucurbitales
order Fabales
order Fagales
order Malpighiales
order Oxalidales
order Rosales
clade eurosids II
family Tapisciaceae
order Brassicales
order Malvales
order Sapindales
clade asterids
order Cornales
order Ericales
clade euasterids I
family Boraginaceae
family Icacinaceae
family Oncothecaceae
family Vahliaceae
order Garryales
order Gentianales
order Lamiales
order Solanales
clade euasterids II
family Bruniaceae
family Columelliaceae [+ family [[Desfontainiaceae]]]
family Eremosynaceae
family Escalloniaceae
family Paracryphiaceae
family Polyosmaceae
family Sphenostemonaceae
family Tribelaceae
order Apiales
order Aquifoliales
order Asterales
order Dipsacales
Note: "+ ..." = optionally separate family, that may be split off from the preceding family.