Bursting out

I photographed Eucalyptus macrocarpa (Mottlecah) today in the Western Australian Botanic Garden in Kings Park, Perth. Mottlecah is said to have the largest flower of all the eucalypts, up to 100 mm diameter. It grows on the coastal sand plains about 100 km north of Perth. In my photo, the expanding flower is 'bursting out' of the cap that covers it.