Elymus athericus (Link) Kerguélen

Foodplant / saprobe
apothecium of Albotricha albotestacea is saprobic on dead leaf of Elytrigia atherica
Remarks: season: 2-8

Foodplant / saprobe
clypeate perithecium of Anthostomella chionostoma is saprobic on dead leaf of Elytrigia atherica
Remarks: season: 9

Foodplant / saprobe
extensive, velvety colony of Cladosporium dematiaceous anamorph of Cladosporium cladosporioides is saprobic on dead, rain-soaked stem of Elytrigia atherica

Foodplant / parasite
Sphacelia anamorph of Claviceps purpurea parasitises inflorescence of Elytrigia atherica
Remarks: season: 7

Foodplant / saprobe
apothecium of Crocicreas culmicola is saprobic on dead stem of Elytrigia atherica
Remarks: season: 7-9

Foodplant / saprobe
apothecium of Lachnum carneolum var. longisporum is saprobic on dead leaf of Elytrigia atherica
Remarks: season: (2-)6-8(-10)

Foodplant / saprobe
stalked apothecium of Lachnum palearum var. palearum is saprobic on dead stem of Elytrigia atherica
Remarks: season: 3-8

Foodplant / saprobe
erumpent apothecium of Lophodermium culmigenum is saprobic on dead stem of Elytrigia atherica
Remarks: season: 3-8

Foodplant / saprobe
immersed perithecium of Micronectriella agropyri is saprobic on dead leaf of Elytrigia atherica

Foodplant / saprobe
extensive, velvety colony of Cladosporium dematiaceous anamorph of Mycosphaerella tulasnei is saprobic on dead, rain-soaked leaf of Elytrigia atherica
Remarks: season: 1-12

In Great Britain and/or Ireland:
Foodplant / spot causer
long, linear, erumpent sorus of Urocystis agropyri causes spots on live, blistered leaf of Elytrigia atherica

Foodplant / spot causer
long, linear, erumpent sori of Urocystis agropyri-campestris causes spots on live, blistered, split into ribbons leaf of Elytrigia atherica
Other: sole host/prey

Foodplant / spot causer
long, linear, erumpent sorus of Ustilago hypodytes causes spots on live, blistered leaf of Elytrigia atherica

Sea couch is the marine version of couch grass. Home owners are not happy with couch grass in their yard because it is so aggressive. Sea couch has the same quality. It is capable of storing nutrients during the winter in its root stocks, thereby retracting these materials for other species. Sea aster is one of the few salt marsh plants which is not displaced. With the present increasing air pollution, sea couch is expected to dominate the marsh vegetation. Grazers eat the young shoots but shun the tougher older plants.

Elymus athericus, the sea couch, is a species of perennial grass in the family Poaceae (true grasses). They have a self-supporting growth form and simple, broad leaves. Individuals can grow to 65 cm tall. The species is invasive to the Mont Saint-Michel bay and has altered the area's ecology.