Several of these flowers found but usually occuring as singles.
No interactions present.
On Portland these are a common species but they never have "dense heads of yellow flowers", often only 2 or 3 blooms per plant.
Lat/Lng: 51.6654, -0.9504
OS grid ref: SU726968
Aston Rowant National Nature Reserve - steep slopes of chalk grassland facing to the West and with a large variety of wild flowers.