This list of systems of plant taxonomy presents “taxonomic systems” used in plant classification.
A taxonomic system is a coherent whole of taxonomic judgments on circumscription and placement of the considered taxa. It is only a “system” if it is applied to a large group of such taxa (for example, all the flowering plants).
There are two main criteria for this list. A system must be taxonomic, that is deal with a large number of plants, by their botanical names. Secondly it must be a system, i.e. deal with the relationships of plants. Although thinking about relationships of plants had started much earlier (see history of plant systematics), such systems really only came into being in the 19th century, as a result of an ever increasing influx from all over the world of newly discovered plant species. The 18th century saw some early systems, which are perhaps precursors rather than full taxonomic systems.
A milestone event was the publication of Species Plantarum by Linnaeus which serves as the starting point of binomial nomenclature for plants. By its size this would qualify to be on this list, but it does not deal with relationships, beyond assigning plants into genera.
Note that a system is not necessarily monolithic and often goes through several stages of development, resulting in several versions of the same system. When a system is widely adopted, many authors will adopt their own particular version of the system. The Cronquist system is well known for existing in many versions.
A. P. de Candolle (1819). Théorie élémentaire de la botanique, ou exposition des principes de la classification naturelle et de l’art de décrire et d’etudier les végétaux (2nd ed.).
A. P. de Candolle et al. (1824–1873). Prodromus systemati naturalis regni vegetabilis sive enumeratio contracta ordinum, generum specierumque plantarum huc usque cognitarum, juxta methodi naturalis normas digesta.Check date values in: |date= (help)
J. Hutchinson (two volumes, 1926–1934; 2nd edition 1959; 3rd edition, 1973). The families of flowering plants, arranged according to a new system based on their probable phylogeny.Check date values in: |date= (help)
Aaron Goldberg (1986). "Classification, Evolution and Phylogeny of the Families of Dicotyledons". Smithsonian Contributions to Botany58: 1–314. (available online: Full text (PDF) here) [there is also a comparison among 11 Dicotyledons systems since 1960 until 1985]
Aaron Goldberg (1989). "Classification, Evolution and Phylogeny of the Families of Monocotyledons". Smithsonian Contributions to Botany71: 1–73. (available online: Full text (PDF) here)
APG (2003). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II". Botanical Journal of the Linnean Society141 (4): 399–436. doi:10.1046/j.1095-8339.2003.t01-1-00158.x.
APG (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III.". Botanical Journal of the Linnean Society161 (2): 399–436. doi:10.1111/j.1095-8339.2009.00996.x.