Current opinion considers the basic stamen configuration of the monocotyledons to be an androecium with two whorls of stamens alternating with two trimerous whorls of tepals (e.g. Dahlgren et al., 1985). We suggest that the primitive monocot androecium consisted of many alternating stamen whorls of six or three stamens each, the outer being arranged as three pairs (which is characteristic for the Alismatales). The evolution of the monocotyledonous androecium is believed to follow two main trends:(1) The building of a reduction series starting from an androecium with numerous stamens arranged in whorls (polycycly). Loss of stamen whorls and replacement of the outer pairs by single stamen leads to dicycly, a general condition of many monocots. The inner, respectively the outer whorls can be further reduced leading to monocycly or obmonocycly. Further reductions lead to unistaminate and unicarpellate flowers.(2) Secondary elaborations, which induce a significant change in the number and the morphology of the stamens. Stamen numbers can be either secondarily increased by the subdivision of complex primordia, by the growth of a receptacular zone and by homeosis, or the stamens may be variously transformed in relation to zygomorphy or asymmetry.