As you walk the heaths of Dorset you cannot fail to notice the small, four-petalled, yellow tormentil (Potentilla erecta) flowers around you. You cannot fail to notice them partly because their cheerful bright yellow flowers stand out in what might otherwise be quite drab surroundings. The other reason is the sheer abundance of them. It is hard to believe that it is a declining species and one that is in need of special protection. It is so easy to think that because something is thriving around you there is no problem and not see the bigger picture; that is where species recording schemes are so essential to provide accurate, unbiased, data upon which to base decisions.
The reason it is declining is the declining amount of suitable habitat. This is an acid soil specialist hence its prevalence on the heaths but it also occurs on acid grassland and that is now a very rare habitat classification.
Tormentil apparently has an unusually high amount of tannin which makes it useful for dying, brewing and medicines. The dye produced from it is not yellow as one might assume but red. The roots are used in various places for brewing beers and the plant itself is used in herbal remedies.