This being lesser skullcap (Scutellaria minor) it does not take a Sherlock Holmes to deduce that there is also a skullcap which is bigger! Skullcap (the larger one) is found near streams and fresh water and, whilst not common, is certainly far from rare. Its lesser cousin, however, is much more restricted in its preferences and so is found far less often.
Lesser skullcap is a member of the bugle family and has the familiar trumpet-shapes flower associated with such species. It is a delicate, sprawling little flower, pink or mauve in colour and the stem is square but, very thin, and also of a pinkish colour. The leaves are pointed and have clearly defined veins. The plant has a mild, minty scent; it does not seem to be the herbal remedy that its larger cousin is, probably because it is not big enough.
It flowers from July through until October and can be found in damp, acidic conditions on heaths and in woods.