Artist overlooks minute aphid regularly seen on flower (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

RA (abbreviation for Royal Academician = artist), before (above, in a down clue = overlooking) M (abbreviation for minute) + alternate letters (regularly seen) of [a] P [h] I [d], then ON . Generic name for a few species of wild flowers (and also some salad leaf vegetables).