Mallow is traditionally used in ointments and in cough syrup. When I was growing up, we usually had bright orange, red, and yellow nasturtiums in a border between the house and the driveway. We used the round leaves as one would use lettuce in sandwiches. They lay nicely flat on the bread, and had a lot more flavor than lettuce. They make good salad greens.
Nasturtium flowers are edible, too.
I have several times been served nasturtium flowers as an edible garnish in restaurants. They really dress up a plate. Nasturtium seeds contain an antibiotic. An infusion made with the seeds, leaves, and flowers fights respiratory infection with fewer side effects than chemical antibiotics. Just a few days after I had written the above paragraphs on nasturtiums, I was out at Lowe's getting some bags of mulch.