Mountain Blue Gum (Eucalyptus deanei)
The Mountain Blue Gums here are between 25 and 50 metres tall. The rainfall at nearby Penrith is only 700 mm per year.
Joseph Maiden named this eucalyptus tree after the engineer and part time botanist, Henry Deane. Here's my Wikipedia article: en.wikipedia.org/wiki/Eucalyptus_deanei
Joe Maiden said this about his railway friend and engineer "I name it in honour of my old friend Henry Deane, M.A., M. Inst. C.E., Engineer-in-Chief for Railway Construction of this State, my coadjutor in much work on the genus published in these Proceedings and whose stimulus and counsel in botanical work I have enjoyed for twenty years. He first drew my attention to this tree in March, 1888, at The Valley, Blue Mountains, and I have had it under observation ever since."