The Eucalyptus cattai is the rarest eucalyptus species in the greater Sydney region. Ecologist Steve Douglas first spotted the unique species on a street corner in Sydney's Hills District 25 years ago. Now, the Cattai is part of a major regeneration program taking place in South-West Sydney.

Steve initially wrote about the species in his masters research paper 'Significant Plants of the Greater Cattai Region' back the 90s, but conservation of the species wouldn't begin for many years.

The Cattai was listed as endangered in 1999 and upgraded to critically endangered in 2015. It is now part of the NSW government's Saving Our Species program and a research and replanting effort taking place at The Australian Botanic Garden in Mt Annan.

Researchers working on preserving this species are trying to understand how Cattai's germinate. While seed pods are present on the plants, only mature trees have been discovered in the wild. (Hence the single tree standing on a street corner.)

“I’d like to know the answer to that – why are there no seedlings? We don’t know what stimulates natural germination,” Enhua Lee, a conservation ecologist from the NSW Department of Environment working on the project told the Sydney Morning Herald.

So far, a number of Cattai varieties have been replanted in a secret national park location chosen for its soils and resilience to the effects of climate change. The rare trees will continue to be monitored until 2026, but their future beyond that is unknown. With the Saving Our Species scheme up for review, Steve emphasises the importance of generating long-term funding for tree conservation.

“There needs to be recurrent funding – not just for five years...to recruit and retain staff with the appropriate skills,” he said. “You’d be losing things before they have got a name and even before they get [an endangered] listing.”