wikitaxa - taxonomy data from Wikipedia/Wikidata/Wikispecies
wikitaxa docs: https://docs.ropensci.org/wikitaxa/
See also the taxize book: https://books.ropensci.org/taxize/
The low level API is meant for power users and gives you more control, but requires more knowledge.
The high level API is meant to be easier and faster to use.