Several weeks ago, when I was returning from Canberra, on 19 September, I stopped for a short while, in Goulburn to have a look at "Governor's Hill" to look for Orchids. Such stops help me to stay alert when travelling on the boring Highway trip, from Canberra to Robertson. Anyway, such a stop is a good excuse for me to go Orchid hunting. Its even better when you find lots of Orchids within 20 metres of the road!
I found a large number of Glossodia major plants in flower, just growing among the heath shrubbery on this rocky hillside, immediately above a cutting on the road leading into Goulburn (from the Marulan end). That was good, as I wanted to publish a post on Glossodias to complete a set of photos of Glossodias which I had taken on Black Mountain, in Canberra.
But I also found many of these plants of Donkey Orchids, which I had not ever seen before. Note how different they are from yesterday's post about D. chryseopsis. Yet they are both in the same genus.
I knew straight away that they were new to me, but which species?
That has taken me a lot longer than anticipated to resolve. It was not that hard, but more a question of being organised enough to find all my reference books, once I returned to Robertson after being away for several weeks.
I am now prepared to assert that this is Diuris pardina - the "Leopard Orchid". The name "pardina" simply means "spotted" - as in "leopard" (leo-pard which literally means a spotted lion).
There are significant differences amongst these plants. Firstly I noticed that some had green stems and some had dark stems, nearly black. Is that difference significant? I do not know.
Look at the size of the labellum wings (left and right of the column, with the white spot - which is in the centre of the flower). In these two close-up photos (above) you can compare the details. One has labellum wings twice the size of the other plant. Then, again, one has two dark spots (one on each side wing). The other is light, with fine dark lines etched on the wings. Quite different details. Are those differences significant? I do not know.
David Jones, in his main reference text says of D. pardina: "exhibits considerable variation in floral colour patterns". That is fine by me, yet in many cases, David Jones is quite dogmatic in using small details to declare some plants to be different species from others. That's also fine. It just makes it very hard for the amateur to work out precisely what one is looking at.
This is an old flower, but it is useful as it shows that the front of the "Donkey ears" (petals) is plain sulphur yellow, but the backs of the petals (the reverse sides) are heavily spotted. That is a feature which Jones mentions as being typical of D. pardina. Some success at last.
That photo above also shows how the lateral sepals of these plants are heavily deflexed, recurved, and crossed. Classic pardina features. Another point of identification. For an even more extreme example, look at the second photo above (the first close-up image). Look at its lateral sepals close-set, and crossed and almost horizontal. Quite extreme angle setting of the sepals, but typical of D. pardina. Note that the third photo (second close-up) has lateral sepals which are straight, and pointed down, without crossing. Do we put that down to individual variation? I guess so.
I like this image, as it shows the front of one flower, and the rear view of another. There is also a third flower - a bud - partially blocking the view, unfortunately. But in the top right of the image there is a clear view of the rear of the "petal" (Donkey's ear). See how that rear of the petal is spotted, whereas the front of the petals on the lower flower is clearly plain. These flowers are all on the one stem of the one plant. So these flowers will be genetically identical (or as close to it as possible). Therefore, this confirms the point made above about the front and rear colours of the flowers being different - the rear part being heavily spotted.
These plants were flowering prolifically, three weeks ago, in Goulburn.
That is nice, as Goulburn has suffered terribly in recent years, from severe drought, but this year's spring has been good for them. More rain than Robertson has had, which is something Goulburn can seldom claim. I am happy for them to have a good season. The people of Goulburn, and especially the farmers, need it.