Eryngium maritimum, the
sea holly or
seaside eryngo, is a species of
Eryngium in the plant family
Apiaceae and native to most
European coastlines. It resembles a
plume thistle in that its flower is burr-shaped, but the flowers are metallic blue rather than mauve. Protected from winds this
dune plant grows to a height of 20 to 60 cm. Although widespread, it is considered endangered in many areas, such as
Germany where its occurrence has been greatly reduced throughout and has become
locally extinct in several districts.