Elymus junceiformis Sand Couch

A glaucous couch-grass which grows in the strandline and foredunes of coastal sand dunes and sometimes in coastal shingle. It has an extensive rhizome system which allows it to colonise and stabilise loose sand, sometimes forming low mounds but it doesn't build high dunes in the way that Marram Grass (Ammophila arenaria) does. Unlike Marram Grass, with which it often grows in foredunes, its leaves remain flat and don't roll-up in dry weather. The distinctive, fat spikelets, which are widely-spaced and barely overlapping on the stem, differ greatly from those of Marram Grass. It hybridises with Common Couch (Elytrigia repens) and Sea Couch (Elytrigia atherica). It is a common maritime species all along the coast of Britain and Ireland and it is found along most of the coast of West Glamorgan except where dunes systems have been lost to development. It is commonly associated with other strandline species such as Sea Rocket (Cakile maritima), Prickly Saltwort (Salsola kali) and Sea Sandwort (Honkenya peploides). British plants are usually referred to subspecies boreoatlanticus (= Elytrigia juncea ssp. boreoatlantica). Sand Couch hybridises with Common Couch (Elymus repens) and the hybrid (Elymus x laxus) may be widespread in West Glamorgan but its exact status here is not clear. It also hybridises with Sea Couch (Elymus athericus) and the hybrid (Elymus x obtusiusculus) is likely to be frequent along the coast in West Glamorgan.

Native

Sand Couch has had a very confusing taxanomic history during the last 50 years during which time generic names such as Agropyron, Elymus and Elytrigia have all been used. It was known initially as Agropyron junceiforme but other names such as Elytrigia juncea, Elytrigia junceiformis, Elymus junceiformis (used by Stace) and Elymus farctus (used by Cope and Gray) are scattered in the literature. According to Stace, Elymus junceiformis is the Atlantic tetraploid and Elymus farctus is the Mediterranean hexaploid. The BSBI Atlas uses the name Elymus junceiformis.