Lavender is the common name applied to various species and cultivars. Often as not they are varieties of Lavendula x intermedia which is the cross of L. angustifolia and L. latifolia. This is one such I think and my favourite though I've never known what it's called!

 The leaves are of a particular grey-green hue and the flowers a pale violet-blue. It has a long flowering period and is very aromatic. The cross is known for a high yield of oil and probably was first cultivated for that reason.

 The one above was being mobbed by bumblebees and honey bees. Lavender is quite possibly the most bee prolific plant at this time of year and I have formed the impression that this particular cultivar attracts more bees than any other.