From a very old (> 40 years), gnarled #Lavandula angusifolia. The flower form and colour suggests 'Hidcote' (selected at Hidcote Manor in Gloucestershire, England by Major Lawrence Waterbury Johnston some time before 1950) but the plant would bloom twice a year, suggesting 'Munstead' (selected by Gertrude Jekll in the UK and introduced to commerce in 1916); but I don't know for sure what cultivar it was.