A hybrid lilac, Syringax chinensis, which forms compact upright bushes and has narrow, pyramidal spikes of pink or purple flowers.
The Rouen lilac is believed to be the result of a natural hybridization between Syringa laciniata and the common lilac, S. vulgaris, at the Botanic Gardens in Rouen in the late 18th cent..
Origin
Mid 19th century; earliest use found in John Loudon (1783–1843), landscape gardener and horticultural writer.