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. [1] In 2009, a linear arrangement of the system was published separately; [2] the APG IV paper includes such an arrangement, cross-referenced to the 2009 one. [1]
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. [1] 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. [3]
Key to symbols used:
Like the earlier APG systems, the APG IV revision is based on a phylogenetic tree for the angiosperms, as shown below. [4]
The Myrtales are an order of flowering plants (angiosperms) placed as a sister to the eurosids II clade as of the publishing of the Eucalyptus grandis genome in June 2014.
Geraniales is a small order of flowering plants, included within the rosid subclade of eudicots. The largest family in the order is Geraniaceae with over 800 species. In addition, the order includes the smaller Francoaceae with about 40 species. Most Geraniales are herbaceous, but there are also shrubs and small trees.
The family Campanulaceae, of the order Asterales, contains nearly 2400 species in 84 genera of herbaceous plants, shrubs, and rarely small trees, often with milky sap. Among them are several familiar garden plants belonging to the genera Campanula (bellflower), Lobelia, and Platycodon (balloonflower). Campanula rapunculus and Codonopsis lanceolata are eaten as vegetables. Lobelia inflata, L. siphilitica and L. tupa and others have been used as medicinal plants. Campanula rapunculoides may be a troublesome weed, particularly in gardens, while Legousia spp. may occur in arable fields.
The Sapotaceae are a family of flowering plants belonging to the order Ericales. The family includes about 800 species of evergreen trees and shrubs in around 65 genera. Their distribution is pantropical.
A system of plant taxonomy, the Takhtajan system of plant classification was published by Armen Takhtajan, in several versions from the 1950s onwards. It is usually compared to the Cronquist system. It admits paraphyletic groups.
Escalloniaceae is a family of flowering plants consisting of about 130 species in eight genera. In the APG II system it is one of eight families in the euasterids II clade (campanulids) that are unplaced as to order. More recent research has provided evidence that two of those families, Eremosynaceae and Tribelaceae, arose from within Escalloniaceae; the Angiosperm Phylogeny Website therefore merges these two families into Escalloniaceae, and also places the family alone in order Escalloniales.
Loasaceae is a family of 15–20 genera and about 200–260 species of flowering plants in the order Cornales, native to the Americas and Africa. Members of the family include annual, biennial and perennial herbaceous plants, and a few shrubs and small trees. Members of the subfamily Loasoideae are known to exhibit rapid thigmonastic stamen movement when pollinators are present.
The Koninklijke Algemeene Vereniging voor Bloembollencultuur, translated from Dutch as the Royal General Association for Bulb Culture, but more commonly known world-wide by the acronym of KAVB, is a trade association for the bulb horticulture sector, and was established in 1860. The association has a rural organization, within which regional groups and departments are active.
The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy being developed by the Angiosperm Phylogeny Group (APG). Published in 2009, it was superseded in 2016 by a further revision, the APG IV system.
This is an alphabetical list of useful timber trees, indigenous and exotic, growing in the Gauteng area of South Africa. These trees range in size up to some 1.5m DBH, such as Cedrus deodara, the Himalayan Cedar. Hobbyists will seek out even small pieces of highly valued timber, such as Buxus macowanii, the South African counterpart of Buxus sempervirens, for turnery or the making of boxes and small items. Despite the wealth of useful woods available in Gauteng, most of the trees, felled or fallen, are dumped or cut into short lengths for fuel. Trees grown in urban or suburban environments are rarely pruned and are consequently often knotty. Timber frequently holds nails, wire and spikes, attesting to a variety of abuse during the lifetime of a tree, and requiring the use of a metal detector by the sawmiller. Garden cuttings and dead leaves are occasionally piled next to trees and burnt, leaving charred scars and inclusions.
The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish on the classification of pteridophytes that reflects knowledge about plant relationships discovered through phylogenetic studies. In 2016, the group published a classification for extant pteridophytes, termed "PPG I". The paper had 94 authors . The classification was presented as a consensus classification supported by the community of fern taxonomists, but it has been partially exclusive and is highly contested. Alternative classifications of ferns exist and are preferred by more general taxonomists.
Zanthoxyloideae is a subfamily of the family Rutaceae.