Ooh I was just looking to see the proper name of sweet alyssum - it turns out it was Alyssum lobularia and is now Lobularia maritima - and found to my surprise, that because it's a member of the brassica family, its flowers and leaves are edible. I love edible flowers and grow as many as I can. At the moment as well as sweet alyssum there are roses, society garlic, johnny jump ups, nasturtiums - we eat the leaves as well, onion chives and calendulas in flower and others that will come on soon.
I have an ambition of being able to walk around my whole garden, not just the veggie patch, picking fruits and flowers to eat. It's amazing to me how many people are nervous, even afraid of eating flowers. I once took a salad with all the ingredients picked from my garden to a potluck dinner and included some heartsease, calendula petals and nasturtium flowers with the salad greens and no-one was game to try it. It was actually quite delicious but the flowers freaked them out. Weird.