Rose-pink five-petalled flowers, each petal deeply notched so the star looks cut rather than grown, on hairy stems at 75 to 90cm from May through August. Despite the name it is pink rather than red; the red distinguishes it from white campion.
It is one of very few decorative perennials genuinely happy in shade. Under deciduous trees, along a north-facing hedge, at the edge of a wood: that is where it belongs and where it looks right, and it will take sun only if the ground stays reliably moist.
There is a botanical quirk worth knowing. The species name dioica means two houses, because male and female flowers are on separate plants. You need both for seed to set, so sow generously rather than putting in a few plants and hoping. It often behaves as a biennial in its first year, leaves one season and flowers the next, then self-seeds reliably into a permanent colony. Grow it near white campion and the two will cross, giving a graduated range from white through pink over a few years, which most people welcome.
