Consult some well-known websites providing plant checklists, namely:
Euro+Med1 http://ww2.bgbm.org/EuroPlusMed
Flora iberica http://www.floraiberica.es, and
Flora-On https://flora-on.pt.
(Euro+Med2 http://www.europlusmed.org is also under development.)
The retrieving of the websites information is performed (in a dirty way) by inspecting the html output and not via API.
Acknowledgments
TMH was funded by the European Social Fund (POCH and NORTE 2020) and by National Funds (MCTES), through a FCT – Fundação para a Ciência a Tecnologia (Portuguese Foundation for Science and Technology) postdoctoral fellowship (SFRH/BPD/115057/2016), as well as by National Funds, through the same foundation, under the project UIDB/04033/2020 (CITAB - Centre for the Research and Technology of Agro-Environmental and Biological Sciences).
Installation
You can install the package from GitLab.
devtools::install_git("https://gitlab.com/point-veg/florae")