Pepperweed was a completely forgotten native herb untill it was re-introduced into the trade by German nursery Rühlemann a few years ago. It is often called perennial cress, but to me its taste appears more similar to horse raddish than to pepper. Anyhow it is a valuable addition to the herb garden. It can be used fresh (in salads or curd) or cooked (in wok dishes or like spinach). 

It is native to the shores of Western Europe, but it can be found growing also along the streams in the interior land. It grows best on moist soils, so it can be used with larger ponds (but keep an eye on it there).