floral organ differentiation stage A floral organ formation stage (PO:0025585) which begins with the differentiation of floral organs (PO:0025395) from the floral organ primordium (PO:0025477) and ends with the beginning of the flowering stage (PO:0007616). During this stage, the process of floral organ development (GO:0048437) occurs, defined as the process whose specific outcome is the progression of the floral organ over time, from its formation to the mature structure. floral organ formation stage