Paeonia peregrina, on the Rockery slope at RHS Wisley today, basking in warm sunshine (truly). The Byzantine Peony or The Red Peony of Constantinople. Marvellous!
An extremely important plant for breeding (the RHS Encyclopedia of Perennials tells me), its unusual combination of pigments being largely responsible for the development of coral-coloured flowers in hybrid peonies. Spreading roots, developing into a diffuse clump, carry red-striped green stems with glossy dark green foliage which has distinctive notched green leaflets. The uniquely bright scarlet-red flowers open in May (or if the season is appalling, June). Happy either in full sun or in part-shade, under deciduous trees. From southern and eastern Europe. 60cm tall and through.