Patricia Taylor in her book on Thomas Blaikie (Tuckwell Press, 2001) says about this rose: “Named “Unique”, it was a centifolia, red in bud, with creamy, white flowers, the ends of the petals slightly tinged with red, and had been discovered in a garden in Suffolk in 1775 by a nurseryman who managed on that occasion to take a single budding from it. Six years later it was flowering at Bagatelle.”
Also references: "a particularly fine illustration of this rose in Mary Lawrence, A Collection of Roses from Nature (London 1799), pl. 4."