They range from scrawny scribbly gums to mighty mountain ash. In fact, there are 700 species and more are being bred and evolving as we breathe.

They have been blamed for the severity of our bushfires due to the oil that courses through their veins and manifests in their leaves.

In the bush, nothing is more delightful than the raw smell of eucalyptus. It is the essence of Australia.

However, apart from being highly combustible, eucalypts cause many deaths falling or taking out drivers when they fall suddenly on roads.

Recently, I came across Eucalyptus Deglupta, also known as the rainbow eucalyptus, Mindanao gum or rainbow gum.

I had always though that eucalypts were Australia's own, but Delgupta is native to the Philippines, Indonesia and Papua New Guinea.

It is the only eucalyptus species that's usually found in rainforest. It's one of only four eucalypt species out of more than 700 that do not occur in Australia.

Of the 15 species found outside Australia, just nine are exclusively non-Australian.

Traveling abroad, it is hard not to notice the impact that our eucalypts have in places as diverse as Spain and California in the US.

In some parts of the world, the fast-growing attributes of eucalypts has provided a natural renewable resource for timber and fuel.

In Australia, there are many imported tress that are seen as weeds with varieties of willow being poisoned on our water courses.

In Spain, there have been protests with farmers protesting against the planting of eucalypts that smother out local vegetation.

They also are seen as nothing more than weeds.

While we plant eucalypts to lower water tables, this is a negative in Spain.

In California, the eucalypt is so common that it is believed to be a Californian native.

An exception is E. globulus, or blue gum, listed as an exotic pest plant of great concern.