Deschampsia flexuosa; the Wavy Hair-grass is very common on Iceland but for the mountains, the barren sandy regions of the interior and the south coast. Once flowering it can easily be identified by the often angular bends in the stems that bear the small spikelet's (hence the name "wavy"). As with other "panicle" grasses one can be confused by the fact that the inflorescences appear quite different in the early stages than the later stages because the panicles at first haven't spread yet.
The Tufted Hair-grass is a member of the grass family (Poaceae, also known as Gramineae). The Icelandic name of the Tufted Hair-grass is Bugðupuntur.