This attractive, architectural plant is unlikely to be mistaken for any other British species. Its stiff, spiny leaves are blue-green and netted with silvery white veins. The small purple blue flowers are packed into a rounded, teasel like head backed by broad spiny bracts and the hairless stems are often tinged with purple.
Flowering occurs from June to September.
Sea-holly is a medium height, clump forming perennial native to coastal sand dunes and occasionally to shingle. It is still reasonably common around the coast south of the Scottish border in the west and the Humber estuary in the east but has disappeared from much of north east England and east Scotland. Although the bulk of this decline occurred in the first half of the twentieth century it is still happening and for reasons that are not fully understood.
Best sown in the autumn.