Alopecurus geniculatus; the Marsh Foxtail has an inflorescence similar to the Meadow Foxtail but it is much smaller. Most striking are the thinner panicles (equal or less than 5mm, about half that of the Meadow Foxtail). Another less striking feature is the more pointed top of the panicle in the Marsh Foxtail. The Marsh Fostail has flowering stems that first grow horizontal (rooting on the nodes) and than bends sharply vertically.
The Marsh Foxtail is common in the lowlands of Iceland. It grows on moist grasslands and similar habitats.
The Marsh Foxtail is a member of the grass family (Poaceae, also known as Gramineae). The Icelandic name of the Marsh Foxtail is Knjáliðagras.