Pretty flowers, nice leaves . . . horrible weed or useful medicinal plant? Actually, all of these apply. If it weren't such an invasive weed, I might even grow it in a perennial bed. Way back when, I learned this one by its common name, Cheeses. I always thought that was a funny name for a plant. And though I'm told that the name Cheeses refers to the seed pods, that doesn't make any more sense than the whole plant being called Cheeses. They are related to the Marsh Mallows and Hollyhocks. All seven types that grow in the U.S. have been brought in from Europe as none are native here.
The demulcent property is what makes this plant useful medicinally and which has since ancient times. Theophrastus mentioned it and Hippocrates gave specific instruction for its use. Pliny said "Whosoever shall take a spoonful of the mallows shall that day be free from all diseases that shall come to him." Depending on the species, either the large roots or the leaves are used to make an infusion. The resulting liquid, mixed with honey, is useful for loosening coughs and relieving sore throats. Grieve's Herbal suggests that a poultice made of any of the mallows will "remove obstinate inflammation ... The fresh leaves, steeped in hot water and applied to the affected parts as poultices, reduce inflammation, and bruised and rubbed upon any place stung by wasps or bees take away the pain, inflammation and swelling." That last use I'll have to try this summer since even though I'd like to have all of the Malva weeded out of the garden, there is always a bit left and the summer when I don't get stung by something is an unusual summer.
As I've been working my way through my book on medicinal plants, one thing has been pretty obvious. Although a number of them have been 'pretty flowers', a lot have been things that might better be classified as weeds. Pretty flowers, yes, but not the kind you want in your perennial border. It does make you think, though, about whether you should leave a few grow as medicinal plants instead of trying to obliterate every last one of the 'weeds'.