Kubitzki system

The Kubitzki system is a system of plant taxonomy devised by Klaus Kubitzki, and is the product of an ongoing survey of vascular plants, entitled "The Families and Genera of Vascular Plants", and extending to 15 volumes in 2018. The survey, in the form of an encyclopedia, is important as a comprehensive, multivolume treatment of the vascular plants, with keys to and descriptions of all families and genera, mostly by specialists in those groups. The Kubitzki system served as the basis for classification in "Mabberley's Plant-Book", a dictionary of the vascular plants. Mabberley states, in his Introduction on page xi of the 2008 edition, that the Kubitzki system "has remained the standard to which other literature is compared".
In ordinal and family arrangements, the classification system in the initial angiosperm volumes closely resembles the Dahlgren system in Monocots and the Cronquist system in Dicots, but later volumes have been influenced by recent molecular phylogenetic studies.
The first volume of the series ("Pteridophytes and Gymnosperms") covered lycophytes, monilophytes, and gymnosperms, and was published in 1990. By 2010, there were nine published volumes, covering 39 of the 59 orders of flowering plants that are recognized in the APG III system. The order Saxifragales is covered except for the genus "Medusandra", which was transferred to it from Malpighiales in 2009. Volume 10 (2011) covers the family Myrtaceae and the orders Cucurbitales and Sapindales. Volume 11 was published in 2014, and two further volumes in 2015. Volumes 2, and 5–7 address dicotyledons, while volumes 3, 4 and 13 address monocotyledons. Volumes 8–12 and 14 deal with eudicots.
Because it is the result of a work in progress, the Kubitzki system is incomplete for those groups of plants that have not yet been covered, and groups that have been completely covered are not revised in light of subsequent knowledge. Since the first volume was published in 1990, a great deal has been learned about plant taxonomy, mostly by phylogenetic analysis of DNA sequences. The classification of ferns has been completely overhauled in that time. And some of the gymnosperm families have been revised.
For the flowering plants, the later volumes of the Kubitzki System follows the Angiosperm Phylogeny Group last revised in 2009 (APG III system), except for the recognition of smaller families. (For a complete listing of all volumes, see Klaus Kubitzki)
Classification.
Summary.
Divisions
Magnoliophyta.
Monocotyledoneae.
4 Superorders
Dicotyledoneae.
In volumes 5,6,7,8 no groups above the taxonomic rank of order were recognized. 
In volume 9 the supraordinal groups Rosidae and Asteridae were recognized.
In volume 10 are treated the Orders Sapindales and Cucurbitales; and the Myrtaceae Family (belonging to Myrtales).