The paper describes the early development of the flower in *Arabidopsis thaliana* from initiation to bud opening, using scanning electron microscopy to detail morphogenesis, growth rate, and surface structure of floral organs. The development is divided into 12 stages, each defined by specific landmark events. Stage 1 begins with the initiation of a floral buttress on the apical meristem, and the process continues through the growth and differentiation of sepals, petals, and stamens, culminating in the formation of the gynoecium. The study estimates the duration of each stage and provides a reference for interpreting the mechanisms of gene action in flower development. The results are compared with those from other Brassicaceae species, highlighting similarities and differences in floral organogenesis. The direction of inflorescence spiral is also discussed, showing that it is randomly determined and maintained throughout the plant's growth. The findings contribute to a better understanding of the genetic control of flower development in *Arabidopsis*.The paper describes the early development of the flower in *Arabidopsis thaliana* from initiation to bud opening, using scanning electron microscopy to detail morphogenesis, growth rate, and surface structure of floral organs. The development is divided into 12 stages, each defined by specific landmark events. Stage 1 begins with the initiation of a floral buttress on the apical meristem, and the process continues through the growth and differentiation of sepals, petals, and stamens, culminating in the formation of the gynoecium. The study estimates the duration of each stage and provides a reference for interpreting the mechanisms of gene action in flower development. The results are compared with those from other Brassicaceae species, highlighting similarities and differences in floral organogenesis. The direction of inflorescence spiral is also discussed, showing that it is randomly determined and maintained throughout the plant's growth. The findings contribute to a better understanding of the genetic control of flower development in *Arabidopsis*.