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 many 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.
Taxonomy_(biology)#Pre-Linnaean taxonomyPre-Linnaean taxonomy
Theophrastus classification
Historia Plantarum (Enquiry into Plants), c. 300 BC
Causes of Plants, c. 300 BC
Dioscorides classification
De Materia Medica, c. 60 AD
Albertus Magnus classification
De Vegetabilibus, c. 1256
Caesalpino classification
De plantis libri XVI, 1583
John Gerard classification
Herball, or Generall Historie of Plantes, 1597
Gaspard Bauhin classification
Pinax theatri botanici, 1623
John Ray classification
Historia Plantarum, 1686–1704
Tournefort classification
Éléments de botanique, 1694
Linnaean systems
Systema Naturae, 1st edition, 1735.