DOI: 10.5061/dryad.xpnvx0kfd
title: Checklists of endemic tracheophytes and bryophytes to the French Overseas Territories

description: A broad range of climatic and biogeographical conditions are represented
 in the French Overseas Territories, from sub-polar to equatorial,
 resulting in a high diversity of endemic species. We mobilized data from
 herbaria, floras, checklists, literature, the expertise of botanists and
 plant ecologists to compile the most complete dataset on endemic vascular
 plants and bryophytes in the 15 French Overseas Territories. To date, 3748
 spermatophytes (seed plants), 244 pteridophytes (ferns and lycophytes) and
 448 bryophytes are strictly endemic to the overseas territories. New
 Caledonia, French Polynesia and Réunion harbour the highest numbers of
 strictly endemic species, yet French Guiana and the French Antilles
 harbour high numbers of regional endemic species due to their proximity
 with other territories. The endemic flora of these territories is highly
 threatened. In particular, 51% of strictly endemic spermatophytes are
 threatened and many species at risk belong to Rubiaceae and Orchidaceae
 families. Around 82% and 69% of strict and regional endemic spermatophytes
 and pteridophytes are found in the Paris herbaria. Only 34% of endemic
 bryophytes have their label information fully databased so that their
 total number in Paris herbaria is not known. Databasing the remaining
 specimens in the collection will greatly enhance future research and
 conservation projects. To facilitate the use of the information we
 compiled, we provide a publicly searchable dataset of the checklist. This
 study not only provides a picture of the flora of French overseas
 territories; it also identifies gaps in knowledge on which future research
 efforts in systematics, ecology and conservation could focus.
description: From TAXREF (version 13 accessed 12/2019), we downloaded the most
 recent data about endemic spermatophytes, pteridophytes and bryophytes in
 the French overseas territories in order to check, revise and update them.
 This work involved local and international participants from museums,
 research institutes, botanical conservatories and Non-Governmental
 Organizations. First, we looked for specimen of overseas endemic species
 in Paris herbarium. Although herbaria are widespread (Thiers 2016), the
 Paris herbarium is one of the most important herbaria in the world in term
 of number of specimens. Around 8 million specimens have been gathered for
 more than three centuries and many belong to species endemic from overseas
 territories (Le Bras et al. 2017). Indeed, in addition to holding types
 from these territories, the Paris herbarium also keeps many other
 specimens collected by botanists either from the Museum or from the
 international community and sent to the Museum as duplicates. Ninety nine
 percent of the specimens are linked to one (the herbarium sheet) or more
 images (e.g. pictures of plants in nature, or microphotographies of
 organs), and 16% have field-collecting information available (Le Bras et
 al. 2017). Collection names for tracheophytes is titled “P” and collection
 name for bryophytes (as well as algae, lichens and fungi) is “PC”. These
 data are freely searchable online via a web interface linked to Sonnerat
 (https://science.mnhn.fr/institution/mnhn/item/search). Herbarium
 specimens enabled taxonomic checks and determination of endemic status of
 plants. For example, we identified species defined as endemic from a
 territory but for which we found an herbarium specimen outside this given
 territory. The endemic status of these species was then checked thanks to
 literature, expert knowledge and global biodiversity databases. For
 species of interest whose field-collecting information was missing in the
 Herbarium database, we directly searched for them in the physical
 collections of Paris or ii) used a participatory science program called
 “Les Herbonautes” from the RECOLNAT infrastructure that allows the
 databasing of herbarium sheets from images available online (Rouhan et al.
 2016). This program was used to database data of endemic species in French
 Polynesia, the French Antilles (Guadeloupe, Martinique, Saint-Barthélemy,
 Saint-Martin), New Caledonia and Wallis and Futuna. We
 also checked literature, Global Species Database and biodiversity portals
 (GBIF, Tropicos, Plants of the World Online) and worked with a network of
 experts to consolidate the taxonomic and biogeographic status of endemic
 species. These data enriched the FEnTOM dataset, and conversely, the
 FEnTOM dataset allowed information in existing checklists to be updated.
 In order to account for statistics closest to the actual endemic species
 diversity, we decided to include in our list some unpublished names that
 are however currently handled by taxonomists working on those taxa and
 that will be validly published later by these authors, and unpublished
 names that are included in databases dealing with the flora of the FOTs
 (e.g. "Nadeaud" for French Polynesia, [Chevillotte et al. 2019];
 Taxonomic Indexes of Réunion, Mayotte, Scattered Islands, [Boullet and
 Picot 2020, Boullet and Dimassi 2020]).