Lathyrus pusillus: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:501970-1

Lathyrus crassipes: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:323133-2

Lathyrus crassipes from South America was synonymized with Lathyrus pusillus from the US on iNaturalist.

I don't know the exact reason for this, but it has led to some misidentifications. I am trying to fix this with this taxon split, but still recommend re-checking the identity of the observations from South America which are now automatically identified as Lathyrus crassipes due to the mapping.