APG II system

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April 2003 by the Angiosperm Phylogeny Group.[1] It was a revision of the first APG system, published in 1998, and was superseded in 2009 by a further revision, the APG III system.

History

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 It was superseded 6½ years later by the APG III system, published in October 2009.

Groups
Cladogram showing the relationships, but excluding taxa not placed within an order

Main groups in the system (all unranked clades between the ranks of class and order):

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.

  • paraphyletic grade basal angiosperms
    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.

References
  1. Angiosperm Phylogeny Group (2003). An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society 141(4): 399-436. doi: 10.1046/j.1095-8339.2003.t01-1-00158.x
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.