Anthoxanthum, the vernal grasses or vernalgrasses (Latinised Greek for "yellow blossom"), is a genus of plants in the grass family.Jepson Manual Treatment The members of Anthoxanthum are widespread in temperate and subtropical parts of Africa and Eurasia, with a few species in tropical mountains. Some species have become naturalized in Australia, New Zealand, and the Americas. Anthoxanthum odoratum is a common species of acidic grassland and bogs in northern Europe. All the species reportedly contain the compound coumarin, used medicinally in many countries.