Botanist, arborist and ecologist, specialising in the eucalypts (genus Eucalyptus, but see note below). Creator/curator of Currency Creek Arboretum in South Australia. Published numerous peer-reviewed articles and books on eucalypts - see http://www.dn.com.au/dean-nicolle.html

I've taken over 8000 herbarium specimens and/or photographic records of eucalypts in the wild, including of every Australian species.

In a project supported by Eucalypt Australia, I have uploaded all my photographic records of eucalypts to iNaturalist, including their field notes and additional diagnostic photos of leaf venation, coppice leaves, and seedlings grown. It will include representatives from every eucalypt species and subspecies.

I now use a single-genus classification for the eucalypts (genus Eucalyptus with 11 subgenera, including E. subg. Corymbia and E. subg. Angophora which are currently recognised as distinct genera in iNat). The single-genus classification of the eucalypts is, in my opinion, best supported by the available evidence and provides the greatest taxonomic utility for workers dealing with this important group of plants.
A full list of all eucalypt species can be found here: http://www.dn.com.au/Classification-Of-The-Eucalypts.pdf
Discussion and justification for a single-genus classification of the eucalypts can be found here: https://onlinelibrary.wiley.com/doi/full/10.1002/tax.13240