After sepal primordial appear, the abaxial sepal primordium begin to overlie the dome-shaped flower primordium, at the same time stamens primordium begein to development, however petal primordium does not appear.

• 形态学观察表明，在花发育早期阶段，无花瓣突变体和有花瓣近等基因系之间花蕾形态学特征基本相同，在花原基上靠近顶端半球形生长锥的下方形成环状隆起，随后分化出4个新月形萼片原基，在将四川大学硕士学位论文尊片合龙时出现雄蕊原基，然而均未观察到花瓣原基。