The sea holly is a beautiful and easily recognisable coastal plant, with blue/green spiky leaves and metallic blue flowers which develop between June and September.
Up to the end of the 19th century the roots of this plant were dug up and candied for use as a sweetmeat and restorative. It is possible that this practice had a significant effect on the distribution of the plant from which it is only now recovering. Sea holly is still common, though thinly spread plant along favourable areas of the Norfolk coastline, and some indicators suggest a slow extension of its range. The major threat to the long term survival and spread of the plant is erosion of its sand dune habitat resulting from either climatic change or human activity. The Norfolk Biodiveristy Action Plan, comprises Habitat Action Plan (HAP) and Species Action Plans (SAP), one of which is titled 'Coastal Sand Dunes', this HAP plan recognises the need to put measures in place to protect the existing habitat and where possible enhance or expand this precious resource.