The images below give a rough idea of achene development: an early anthesis stage (two on the right) and a pre–maturity stage (on the left). Note: The scales for the three images are different. The blue arrows indicate the length of the the achene body; the green arrows, the beak. 'A' indicates the top of the pappus; 'B', the base of the pappus, at the annulus; 'C', the point of attachment at the receptacle. The similarity in pappus length (between 'A' and 'B') is deceptive in the absence of a common scale. The pappus lengthens during anthesis, often as much as 2 mm. In the advanced stage not all beaks have developed to the same extent, probably indicating differences in timing of opening of the florets and/or fertilization. The pistillate florets in the advance stage are almost completely concealed within the pappus, and probably would not have been visible, had the head not been dissected.
