Floral diagrams are presented for twenty-eight families out of ten orders of monocots, covering the diversity and evolutionary trends within this largely homogeneous group. The monocots are basically defined by their trimerous Bauplan, regulating the structure of the flower as well as its evolution. The basalmost orders demonstrate greater variation with higher or lower stamen numbers, while higher groups have evolved within the constraint of a pentacyclic arrangement that has changed very little. Variations in flower morphology as adaptations to different pollination systems are regulated by hypanthial growth, reductions of organs or stamen increases, and monosymmetry.