The dog violet is usually of a lighter blue than the sweet-smelling species.
It appears in May and June, in which latter month it deposits its eggs on the dog violet (Viola canina).
The caterpillar, also, feeds on the same plant (dog violet) as Selene.
The dog violet has five green sepals with very sharp points, and the lower part of each sepal is slightly swollen.
In the Heartsease the broadest petal has a very small tube at the narrow end, the same as in the dog violet.
dog violet (Viola canina) is so-called contemptuously because scentless.
Similar remarks may be applied to our two common plants, the sweet violet (Viola odorata) and the dog violet (Viola canina).