Can anyone help identify this please? My Dad got the original from a cutting years ago, and propagates it each year. It's not hardy so he grows it in pots and brings it indoors in the winter (SE England - the photos were taken today). He says he thinks it's from the 'lavender family' but from the leaves I don't think that can be true. Neither leaves nor flowers have scent. The flower spikes are about 8 cm long.