The Wiki page clearly describes taxonomic tagging with the use of the `genus=*` and `species=*` tags and explains in the section about palms that neither of those keys would be accurate because "palm" is a family, not a genus or species.

From my understanding, the way I have tagged the palm trees (`family=Arecaceae` + `family:en=Palm` + `family:wikidata=Q14080`) is the most accurate approach.

Refer to this thread on the forums, where these tags were discussed: https://community.openstreetmap.org/t/leaf-type-palm-is-anything-wrong-with-it/109646