Elymus athericus

Elymus athericus, the sea couch (also classified as Thinopyrum acutum or Elytrigia atherica), is a stout, rhizomatous perennial grass of the Poaceae family native to coastal western and southern Europe and the Mediterranean, where it is a characteristic species of the upper salt marsh and brackish coastal grassland. From long, vigorous, creeping rhizomes the plant produces erect, smooth, glaucous culms forty to one hundred and twenty centimetres tall, forming extensive monodominant stands. The flat to inrolled, stiff, blue-green leaf blades are sharply pointed and finely ribbed. In summer the inflorescence is a stiff, slender, two-ranked spike up to twenty centimetres long, bearing solitary, several-flowered spikelets pressed close to the rachis with their broad faces, the glumes sharply keeled. The species is salt-tolerant and aggressive on stabilised coastal sediments.