The name Eucalyptus is derived from two Greek words: eu = well and kaluptos = covered.
What this name actually refers to is the operculum.
An operculum is a cap that is made of fused sepals and/or petals, enclosing the stamens of the flower. As the stamens grow the cap is forced off, revealing the fluffy stamens, which explode outwards like a fireworks display.
These flowers are from the Eucalyptus Kingsmillii, also known as Kingsmill’s mallee.
King’s Park Botanical Gardens, Perth Australia – August, 2011