Are the flowers of Veronica serpyllifolia ssp. humifusa ever blue?

摘要

On a number of occasions in the Cairngorms area, in north-east Scotland, I have found plants of Veronica serpyllifolia (Thyme-leaved Speedwell) that appeared to be ssp. humifusa. Procumbent rooting stems, more rounded leaves, short few-flowered glandular-hairy racemes of large flowers, all pointed to the montane subspecies. However, none of these plants had all blue flowers, and the many floras and other references I have access to seemed most insistent on this point.