There are many kinds of Acorus plants.In older literature and on many site, there is still a lot confusion with the name Acorus calamus equally but wrongfully applied to Acorus americanus. Acorus belong to Acoraceae family and the genus name of this plant is Acorus. This flowering plants is a genus of monocot. The name Acorus is derived from the Greek word acoron, a name used by Dioscorides which in turn was derived from cordon, meaning "Pupil" because it was used in herbal medicine as a medicine for inflammation of the eye. It is native to North America, Northern and Eastern Asia. It is naturalized in Southern Asia and Europe from ancient cultivation. Let me share something here about Acorus gramineus. The gramineus is a Japanese sweet flag that is aquatic or wetland perennial with semievergreen grasslike foliage. It has narrow 6-14 inches glossy leaves and looks like thick, lush grass. Japanese sweet flag is used along pond margins and at the edges of water gardens. It spread aggressively by rhizomes and will eventually produce a seamless turf, making a beautiful ground-cover for the front of a bog garden. If you plan to plant this plant please plant them in very moist soil. It does just fine in the wetland zone along ponds and ornamental pools. It can be grown in regular garden situaltions but must be watered frequently. There are only two kinds of species in the genus of Acorus plants. The A calamus or sweet flag and the source of oil of calamus. They are used medicinally and in perfumes and soaps.