I bought this plant as Polygala grandiflora 'Nana' (ht 1.2 m) - said to be a dwarf form of the shrub known as milkwort. I am not really sure if this is the correct name - the genus Polygala is large and confusing! I grow mine in a bright blue pot, which gives a colourful contrast to the rich purple, pea-like flowers with prominent white fringes of stamens, which appear in late winter and spring. This plant enjoys a dry, sunny position. Note that in some areas, certain species of Polygala are regarded as noxious weeds. I haven't had any problem with mine self-seeding so far, but clipping the plant back after flowering reduce the risk, as well as making it more compact, as it can get a bit straggly if left unrpuned. It can be cut back quite hard. This genus belongs to the Polygalaceae family.
Postscript: My plant eventually languished in its pot. I think if I grow it again I will put it in the ground. I don't think they are very long-lived in any case. I still admire it in other people's gardens in spring!