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Snapshots of the taxonomy

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Background Information

The standardisation and cataloguing of plant names is a critical step in various fields of biology, including biodiversity, biogeography, and vegetation research. The WFO Plant List is the most comprehensive and authoritative list of the world’s plants, maintained by the global community of taxonomic experts as a free and open access resource.

WFO Plant List replacing The Plant List

The WFO Plant List was launched in May 2021 as a next generation replacement for The Plant List, recognising the continuing need for a user-friendly, citable static list of all plant species. The WFO Plant List is a snapshot in time of the WFO Taxonomic Backbone – the dynamic global consensus classification used by WFO to organise and present floristic data.

Like The Plant List, the WFO Plant List is a working list of all known plant species, but differs in that it is curated by the international taxonomic community. The Plant List has not been updated since 2013. The WFO Plant List aims to provide the highest quality information on which to base research, conservation, and the sustainable use of the world’s biological resources.

The Plant List

The Plant List (TPL) was published in December 2010 as a direct response to Target 1 of the Global Strategy for Plant Conservation (GSPC) 20022010: to establish a widely accessible working list of all plant species, as a step towards a complete world Flora.’ The GSPC was adopted in 2002 by the 193 governments who are Parties to the Convention on Biological Diversity (CBD), and was designed as a framework for action to halt the loss of plant diversity.

TPL was a collaborative venture coordinated by the Royal Botanic Gardens, Kew and the Missouri Botanical Garden, combining multiple checklist databases using computer algorithms (see TPL about pages). With comprehensive coverage of species of vascular plants (flowering plants, conifers, ferns and their allies) and of bryophytes (mosses and liverworts), TPL included almost 1.3 million scientific plant names, of which around 350,000 were accepted species.

TPL was recognised as not perfect but representing work in progress, and aimed to stimulate further work. The latest edition of TPL, Version 1.1, was released in September 2013, based on data harvested in May 2012.

WFO Plant List

World Flora Online (WFO) is a consortium of taxonomic institutes and organisations working together to develop a global resource of descriptions and other botanical data linked to a consensus classification of the world’s plants. The WFO consortium was formed in 2012 and the WFO portal launched in 2020, in fulfilment of the revised GSPC Target 1 for 20112020: to produce an online Flora of all known plants.

WFO brings together and presents floristic data from around the world using a consensus classification – the WFO Taxonomic Backbone – a comprehensive global taxonomic hierarchy of accepted names and synonyms. This was developed using TPL 1.1 as the starting point, with the intention that Taxonomic Expert Networks (TENs) will be assigned segments of the taxonomic backbone to curate. Since then, the higher classification (family and above) has been updated to APG IV and the equivalents in other groups (see below), and new names have been incorporated from nomenclators — the International Plant Name Index (IPNI) for vascular plants, and Tropicos for bryophytes.

One of the limitations of TPL was that there was no provision to incorporate corrections from expert users. In contrast, WFO puts the curation of its taxonomic backbone into the hands of the international taxonomic community. TENs are providing updated classifications either directly, or via the World Checklist of Vascular Plants (WCVP), and the classification for non-TEN groups is updated using WCVP. Further information on the World Flora Online and the management of the WFO Taxonomic Backbone is given in the WFO About Pages.

The WFO Taxonomic Backbone is dynamic and ever changing, as it is continually updated as corrections and new names are incorporated and taxonomies are revised. But many users need to refer to a static list of accepted plant names and their synonyms, and the WFO Plant List fulfils this requirement. The WFO Plant List is a snapshot of the WFO Taxonomic Backbone – giving the classification information at a particular point in time, and providing a stable reference to which people can refer and cite in their publications.

Versioned updates of the WFO Plant List will be produced, with the old versions archived. The latest version is shown on the WFO Plant List homepage, but users can also view archived versions and step back in time to see how plant names were handled in the.

The data included in the WFO Plant List includes the taxonomic names (from order to family through sub-species level), accepted names and synonyms, and literature citation of the original description. All names included in the taxonomic backbone are assigned a globally unique identifier that is citable, and linked to other digital resources, such as indices of botanical nomenclature. When used in versions of the WFO Plant List the WFO ID is augmented with the version number, so users can use deep links to a name and the use of that name.

The WFO Plant List website was designed and implimented by Nye Hughes (Dalrymple) in collaboration with Royal Botanic Garden Edinburgh, using the WFO Plant List API (Application Programming Interface) developed by Roger Hyam.

Using WFO Plant List data

The entire WFO Plant List dataset is Public Domain (CC0) and can be downloaded as a whole from the page of archived versions, or as subsets for orders, families and genera from within the WFO Plant List itself. 

The data can also be accessed via the WFO Plant List API developed by Roger Hyam at the Royal Botanic Garden Edinburgh.

A name matching facility, WorldFlora, has been developed by Roeland Kindt as an R Package pipeline for checking plant names. Further information is given in the Snapshot Archive.

Infraspecific names in WFO Plant List

The names of some subspecies and varieties of plant are included in the WFO Plant List primarily where names of species rank are synonyms of accepted infraspecific names, and where they were available from the contributing data sets. The WFO Plant List does not aspire to comprehensive coverage of the names of infraspecific taxa (subspecies, varieties, forms, etc.).

Higher classifications used in WFO

The WFO consortium had adopted the following published classifications for families and higher groups. In some instances, these have been modified following requests from the respective Taxonomic Expert Network where significant advancements have been made in taxonomic understanding.

Angiosperms (Trachaeophyta in part)
APG IV: The Angiosperm Phylogeny Group (2016). An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV. Botanical Journal of the Linnean Society, 181: 120. DOI: 10.1111/boj.12385

Gymnosperms (Trachaeophyta in part)
Christenhusz, M.J.M. et al. (2011), A new classification and linear sequence of extant gymnosperms. Phytotaxa, 19: 5570. DOI: 10.11646/phytotaxa.19.1.3

Ferns and allies (Pteridophyta)
PPG I: The Pteridophyte Phylogeny Group (2016), A community-derived classification for extant lycophytes and ferns. Journal of Systematics and Evolution, 54: 563603. DOI: 10.1111/jse.12229

Mosses (Bryophyta)
Goffinet, B., W.R Buck & A.J. Shaw (2008), Morphology and classification of the Bryophyta, in Goffinet & Shaw (eds.) Bryophyte Biology, 2nd edition, p. 55138, Cambridge University Press. On-line updated version available here.

Hornworts & Liverworts (Anthocerotophyta & Marchantiophyta)
Söderström, L. et al. (2016), World checklist of hornworts and liverworts. PhytoKeys 59: 1828. DOI: 10.3897/phytokeys.59.6261