This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
Cortusa embraces only one species, the C. Matthioli. It is near akin to Primula, and in general appearance and habit of growth resembles some of the species of that family. It is found, in company with several of the Alpine Primulas, inhabiting moist valleys at high elevations on the Alps of Italy and neighbouring countries, and is therefore best adapted for cultivating on rockwork, where partial shade and abundant moisture can be given it in the growing season. In warm sheltered situations, where moisture abounds in the atmosphere and the soil is naturally or artificially well drained, it may succeed in the open ground; but there are very few places in this country where these conditions exist in the degree necessary to the wellbeing of this little plant. It will therefore be safer to keep it on rockwork, of which it is more characteristic than the open dressed border, and in cold wet localities less or more of it should be kept in pots and wintered in a cold dry frame to provide against loss of stock. Rich loam, or a little peat and loam, with a liberal allowance of sharp sand, forms a congenial compost. Whether in pots or otherwise, it must be remembered that ample drainage should be provided, and copious supplies of water during the time it is making growth.
Propagate by seeds and division) the latter immediately after flowering, and the seeds in the way recommended for Primula. It is rather a handsome little plant, with nothing very showy either in the mass or colour of the flowers, but will always be interesting to those who take a delight in the simple beauty of Alpine plants. The leaves are nearly round, heart-shaped at the base, very slightly lobed, and sharply toothed. The flower-stems are about 6 or 8 inches high, terminating in a small loose umbel of few small bright red flowers on drooping foot-stalks; the corolla is slightly bell-shaped, and deeply divided in five segments. Flowers in April, May, and June.