Puccinellia capillaris - also known as Puccinellia distans ssp. borealis; Reflexed Saltmarsh-grass is a prostrate growing grass usually in coastal regions but has been found on some inland spots as well. Although Puccinellia's are genererally considered to be salt marsh plants, this specific species grows on a variety of soils like gravelly soils. It is very similar to another Saltmarsh-grass growing on Iceland being the Northern Saltmarsh-grass (Puccinellia coarctata also known as Puccinellia nutkaensis). They can best be recognized in their later bloom-phase: The reflexed Saltmarsh-grass (as the name indicates) has its flowering stems reflexed outwards, even backwards.
It is a member of the grass family gramineae also known as Poaceae.