In higher plants, flowers comprise distinct nonreproductive and reproductive organs, playing a pivotal role in both seed production and plant propagation. Although flower shapes exhibit significant variation across angiosperms, the fundamental genetic components governing floral organ development remain evolutionarily conserved. Over the past three decades, extensive research has focused on the genetic basis, cellular and molecular events regulating floral initiation, determination, patterning, organ boundary formation, cell differentiation, and the growth and development of floral organs in Arabidopsis (Arabidopsis thaliana) and other plant model systems, including snapdragon (Antirrhinum majus), petunia (Petunia hybrida), rice (Oryza sativa), and maize (Zea mays). In this chapter, our objective is to update the conserved and diverse components that control flower specification in higher plants. We specifically focus on rice in comparison with maize and Arabidopsis. Additionally, we aim to provide an overview of regulatory factors and signaling pathways involved in the specification of floral organ patterning.