Distribution of the differentially expressed genes. Venn diagram shows distribution of genes which are significantly differentially expressed in different stages of individual flower types. Differential expression is based on one-sample t-test p-values. The number of differentially expressed genes increases with development and correlates with the morphological changes detected in flower types. Many of the genes show stage-specific expression. Genes expressed only at stage 3 and those common to stages 5 and 6 were analyzed more closely.