Herbaceous plants whose seeds have only one cotyledon are called monocots. The family of monocotyledonous plants is called monocotyledonous family. Dr. Arthur Cronquist (1981) grouped all herbaceous plants into 380 genera. Among them, the number of monocots is 65. Butomaceae is the first family of monocots, Poaceae is the 34th family and Orchidaceae is the last 65th family.