Definission: Tall-grass perennial swards on mobile coastal dunes of the seaboards of Europe, North America, Greenland, North Africa, Middle East and the Caspian Sea
Definission: Of plant duration, a plant whose life span extends over more than two growing seasons, c.f. annual, biennial, ephemeral, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic
