Viola riviniana, the common dog-violet, is a species of flowering plant in the family Violaceae, native to Eurasia and Africa.[1] It is also called wood violet[1] and dog violet.[1] It inhabits woodland edges, grassland and shady hedge banks. It is found in all soils except those which are acid or very wet.
Growing to 10 cm (3.9 in) tall and 50 cm (20 in) broad, this prostrate perennial has dark green, heart-shaped leaves and produces multiple violet coloured flowers in May and June.[2]
Viola odorata (sweet violet) – fragrant; all the leaves are located at the base of the plant; stipules are gland-tipped
Viola canina (heath dog violet) – clear blue flowers; narrower leaves; smaller teeth on the stipules
Viola palustris (marsh violet) – found in wet places; leaves are kidney-shaped; grows from underground creeping stems; dark-veined flowers; stipules without teeth
Viola labradorica (alpine violet) – V. riviniana is sometimes sold by nurseries as V. labradorica
Hybrids
This species hybridises with early dog-violet (V. reichenbachiana) to produce Viola × bavarica.
Partridge, James (2007) Viola × bavarica: the punctual Dog-violet BSBI News 106:8–9 (illustrated with colour photographs on inside back cover of this edition)