Common Peppercress (Lepidium africanum ) is a roadside regular around Gawler. It can be trusted to show itself around Spring and the beginning of Summer.
As its name suggests, it has a peppery taste, and the whole plant can be eaten. Some folks say its a substitute for Tarragon.
It doesn’t have a medicinal use in European herbalism, but in its African home, its leaves are used is used to treat coughs, colds and flu. Here too, the dried unripe seeds are used for stomach ulcers.
I’m not sure how Common Peppercress works but I’ve found it to have a mildly irritating quality, causing redness if enough is rubbed on the skin, which may points to its possible use for sprains and strains.