The central florets are beginning to open
Two of 4 anthers have emerged from the central flower. Anthers in more peripheral flowers have opened revealing the pollen. Anthers from the outer marginal flowers have already detached from the stamen filaments and have lost their purple colour.
The carpels of the outer flowers have now grown much larger
Almost all of the florets have opened. Pollen is lying on the large outer petal. An aphid is partially hidden between overlapping petals sat the bottom of the picture.
A dissected flower showing the positions of the developing ovaries. Notice the central cavity
A closer view
The depth of the pappus and the position of the ovary are shown in this dissected flower