The Plant List has been developed by experts from the Kew Botanical Garden in London and the Missouri Botanical Garden. In line with the nomenclature of these two botanical gardens, they have formed a list of 1.04 million species names. Of the complete list, about 300,000 names are accepted species names and another 480,000 names have been considered synonyms. It has not yet been resolved if the remaining 260,000 names are species names or synonyms.
This is a work carried out within the Global Plant Conservation Strategy. This strategy was launched in 1999 and the last meeting agreed that the first objective for the period 2011-2020 should be the elaboration of an on-line list of known plants. "It is essential," said the director of the Missouri Botanical Garden, "to have an exhaustive list of the world's flora in order to address plant conservation efforts."