( A.Harkes, Hazerswoude, Netherlands 1988.)
In foliage and flowers very similar to ´Serotina´. It grows more freely than ´Serotina´with darker leaves and flowerbuds and bluish purple young stems. The name serpentine means: relating to snakes and referring to the twigs.
Found by a Dutch nurseryman in the 1960´s on the Dutch island Texel. For many years it was sold as ´Serotina´, but in 1988 a cultivar new name was given by Harry J. v.d. Laar.