Ballota nigra Black Horehound CC DDD N
This picture flatters what is usually a fairly ordinary roadside plant with dull purple flowers up the main stem. I look for it in hedgerows whether in country or town. It flowers in late summer and continues until the first frosts so in a mild winter one or two flowers are still around in November or even December. This British Isles plant is ssp meridionalis.
The odd English name has nothing to do with dogs or hounds. The Old English name for this plant was Hune while hoariness was denoted by har = har hune which has become horehound.
It is extremely common in England absent from much of Mid wales, present in Scotland mostly on the south east coastal areas and uncommon in Ireland.