The Sweet vernal grass (Anthoxanthum odoratum) belongs to Poaceaea (the Grass family). It is a perennial herb that is native to Europe and North Asia. It was introduced into Japan as a meadow grass in Meiji Era (about 130 years ago). Nowadays it is naturalized in roadsides and meadows. This grass can reach 30-45 cm in height and the stems are covered with sparse hairs. The panicles are borne and bloom flowers from April to July. The exserted stigmas seem like white threads. The dried plants have a flavor of coumarin odor.