Fig. 4.

The ring meristem of E. californica forming stamen primordia. (A) Bud of a late stage 4 flower in which the floral dome separates from the ring meristem (indicated by a blurred orange line). (B) Stage 5 bud showing the continuous formation of stamen primordia while the gynoecium has already initiated. (C) Stage 6 bud showing the formation of new stamen primordia (white arrow) at the time when the early stamens already form a flat surface for microsporangia initiation. The sepals were removed in all images, and staging was done according to Becker et al. (2005). FD, floral dome; G, gynoecium; P, petal; RM, ring meristem; S, stamen; SP, stamen primordium. Scale bar in A = 86 μm, in B = 100 μm, in C = 120 μm.