Hieróchloë odorata; The Holy-grass grows in brushes, heatherlands and grasslands. The spreading panicles are characteristic, but other grasses also show this feature. Most notable are the Smooth Meadow-grass (Poa pratensis) and the Rough Meadow-grass (Poa trivialis). The holy grass can be told from both Poa's by the rather broad and flat leaves. This plant also has the distinctive scent of coumarin. Another coumarin-scenting grass, commonly growing on Iceland, is Anthoxanthum odoratum (Sweet Vernal-grass). This grass has a terminal 1-spiked inflorescence.
They are all member of the grass family (Poaceae also known as Gramineae)