APG III system in the context of "List of systems of plant taxonomy"

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.

Theaceae (/θiˈeɪsii/), the tea family, is a family of flowering plants comprising shrubs and trees, including the economically important tea plant, and the ornamental camellias. It can be described as having from seven to 40 genera, depending on the source and the method of circumscription used. The family Ternstroemiaceae has been included within Theaceae; however, the APG III system of 2009 places it instead in Pentaphylacaceae. Most but not all species are native to China and East Asia.

Caryophyllaceae, commonly called the pink family or carnation family, is a family of flowering plants. It is included in the eudicot order Caryophyllales in the APG III system, alongside 33 other families, including Amaranthaceae, Cactaceae, and Polygonaceae. It is a large family, with 105 genera and about 2,625 known species.

This cosmopolitan family of mostly herbaceous plants is best represented in temperate climates, with a few species growing on tropical mountains. Some of the more commonly known members include pinks and carnations (Dianthus), and firepink and campions (Silene). Many species are grown as ornamental plants, and some species are widespread weeds. Most species grow in the Mediterranean and bordering regions of Europe and Asia. The number of genera and species in the Southern Hemisphere is rather small, although the family does contain Antarctic pearlwort (Colobanthus quitensis), the world's southernmost dicot, which is one of only two flowering plants found in Antarctica.

Liliales is an order of monocotyledonous flowering plants in the Angiosperm Phylogeny Group and Angiosperm Phylogeny Web system, within the lilioid monocots. This order of necessity includes the family Liliaceae. The APG III system (2009) places this order in the monocot clade. In APG III, the family Luzuriagaceae is combined with the family Alstroemeriaceae and the family Petermanniaceae is recognized. Both the order Lililiales and the family Liliaceae have had a widely disputed history, with the circumscription varying greatly from one taxonomist to another. Previous members of this order, which at one stage included most monocots with conspicuous tepals and lacking starch in the endosperm are now distributed over three orders, Liliales, Dioscoreales and Asparagales, using predominantly molecular phylogenetics. The newly delimited Liliales is monophyletic, with ten families. Well known plants from the order include Lilium (lily), tulip, the North American wildflower Trillium, and greenbrier.

Thus circumscribed, this order consists mostly of herbaceous plants, but lianas and shrubs also occur. They are mostly perennial plants, with food storage organs such as corms or rhizomes. The family Corsiaceae is notable for being heterotrophic.

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.

The Dilleniales are an order of flowering plants, potentially containing one family, Dilleniaceae. The APG III system of 2009, like the earlier APG II system of 2003, left the Dilleniaceae unplaced as to order, while noting that the name Dilleniales was available. Stevens at the Angiosperm Phylogeny Website has subsequently placed Dilleniaceae in the order Dilleniales.

The Cronquist system, of 1981, recognized such an order and placed it in subclass Dilleniidae. It used the following circumscription:

Icacinales is an order of flowering plants.

The order did not exist in the 2009 APG III system, and was added in the 2016 APG IV system, including two families, Icacinaceae and Oncothecaceae, which were both unplaced families in APG III.

Cyclamen (US: /ˈsaɪkləmən/ SY-klə-mən or UK: /ˈsɪkləmən/ SIK-lə-mən) is a genus of 25 species of perennial flowering plants in the family Primulaceae. In English, it is known by the common names sowbread or swinebread. Cyclamen species are native to Europe and the Mediterranean Basin east to the Caucasus and Iran, with one species in Somalia. They grow from tubers and are valued for their flowers with upswept petals and variably patterned leaves.

It was traditionally classified in the family Primulaceae, was reclassified in the family Myrsinaceae in 2000 and finally, in 2009 with the introduction of the APG III system, was returned to the subfamily Myrsinoideae within the family Primulaceae.

Bitterroot (Lewisia rediviva) is a small perennial herb in the family Montiaceae. Its specific epithet rediviva ("revived, reborn") refers to its ability to regenerate from dry and seemingly dead roots.

The genus Lewisia was moved in 2009 from the purslane family (Portulacaceae) with adoption of the APG III system, to the family Montiaceae.