see discussion here:
https://www.inaturalist.org/flags/574802

POWO lists V. pallens as a synonym of V. palustris var. palustris (based on the ID of the type), but "V. pallens" and "V. macloskeyi var. pallens" as IDs have been widely used to mean what is currently meant by "V. minuscula". This change reflects that (actual) usage.

Plants ID'd as "V. macloskeyi" (without a variety designated) in eastern North America presumably also refer to V. minuscula - that will be handled in another taxon change.

https://www.biorxiv.org/content/10.1101/2022.04.22.489152v1.full.pdf
https://people.ohio.edu/ballardh/vgpena/taxa/violaminuscula.htm