Thanks for putting up this spring photo - there are very few recorded locations of Black Mountain Donkey orchid on Bruce Ridge and I am a little concerned that this may be due to its high mountain bike usage and what the crisscrossing of it with tracks does to the fungal mycrrorhiza. It is species that seems favoured by fire and on Black Mountain is more common on lower flatter slopes which seems to make Bruce Ridge otherwise favourable habitat.
I am sorry to say but this looks like Diuris sulphurea. The horizontal dorsal sepal with the two blotches is a much closer match for sulphurea than it is to nigromontana. The flowering time of early September is quite early for sulphurea though.
Thank you both for the comments. I was going back and forth trying to positively ID. I’ve mistakenly put in the wrong date, it was the 20th November 2021.