[MattBlissett]

As azeirah writes, subreddits or Facebook groups for people interested in the particular group or location will often help.

For general wild plants and animals (and fungi and everything else) there's a computer vision tool from iNaturalist, which can be used independently [1], or when submitting an observation to the site -- by web browser or in the app. I usually start with that, then look at other observations on iNaturalist and Wikipedia pages for the species.

If the photos are of ornamental plants, I think PlantNet's [2] model is trained on them.

(I work at GBIF[3], where suitable data from iNaturalist[3b] and soon PlantNet is sent, and can then be freely downloaded and used in research etc.)

[1] https://www.inaturalist.org/computer_vision_demo

[2] https://plantnet.org/

[3] https://www.gbif.org/

[3b] https://www.gbif.org/dataset/50c9509d-22c7-4a22-a47d-8c48425...