In aboriginal culture, the eucalyptus tree provided a healing oilwhich treated and protected against illnesses. It was often used in spiritual rituals to purify. 

The name has greek roots in words meaning well covered. 

Flowering as autumn comes, they symbolize a change of the seasons. They can represent a an excitement for change. 

The delicate petals fall once the blooms are over, and therefore can represent the transience of life, fragility of beauty and impermanence.

Chrysanthemums are one of the blooms still available on All Souls Day, this had led to many European countries using them to decorate graves of loved ones. 

Chrysanthemum flowers are long lasting leading to them also having symbolism for long life.