Dave, is it possible to show the linked plants while in edit mode? It would make it easier to know what tagged plant isn't linked to the DB.
Occasionally I'll edit someone's image set (I try to remember to Treemail the author) so the cultivar is linked to the DB. It's usually the result of a misspelling or something similar. I hope no one is offended, but these side by side comparisons are just so helpful in the database.
