Adding a note here regarding some of the recent confusion.

The former two taxa arvensis arvensis and arvensis caerulea produced a "pinkish" hybrid that in literature was referred to as form amoena. When caerulea was split as a separate taxon, the hybrid form was then by virtue elevated to status as × amoena. This apparently has caused misunderstandings here as someone has recently merged × amoena with the species amoena, which is apparently the correct name for an independent species formerly known as L. buxifolia. The hybrid was merged with this species name and then buxifolia was taxon swapped into amoena, which lumped two unrelated plants.

POWO places "amoena" (in the sense of × amoena, the hybrid) as a synonym of arvensis, but it is nonsensical to synonymize a hybrid with one of the parents in said hybrid combination. Most likely this listed synonymy is prior to the split of arvensis and caerulea, where past authors decided not to bother recognizing any of the form or varieties within arvensis. As a result, those publications are often cited as justification for synonymy, even if they do not contain any actual reasoning, evidence, or mention of that decision. Personal preference of authors in deciding to look at or overlook form and variety names has frequently caused issues like this to arise in the past.

One issue remains however, which is that now we have two distinct plants with the same epithet. Normally, this would require one to have a new name published, but that's outside the scope of iNaturalist. As such, for now it seems the only reasonable scenario is to keep both as they are, and await any future amendments.