This variety is restricted to the Blackdown Tableland, an isolated mesa-like, sandstone plateau about half way between Emerald and Rockhampton, and a fraction south of the Tropic of Capricorn. Blackdown is about ten kms wide and 30 kms long. See main menu under heading; Distribution Map. Var. blackdownensemay extend further to the south and west, into the non-accessible Expedition Range.
I am going to make a big statement right up front. The best forms of var. blackdownense are possibly the most attractive members of the D. speciosum complex. You could never know this of course unless you see a hell of a lot of specimens in flower. Rarely is it seen on a show bench however.
In 2012, it was my extreme good fortune to visit the Tableland amid what was surely the biggest season for blooming ever. We saw in great detail literally thousands of racemes during the days we explored the place. In three prior visits over 20 years we had not seen a single raceme. It is fickle to flower and predicting the season from 2000 kms away is nigh impossible.
Firstly, var. blackdownense has its own characteristics, and these make it distinct from other varieties. Flowers are not usually bigger then 50 mms, but overall they seem to average out at about 40mms. They tend to be as wide as they are deep. The labellum is quite long for the size of the flower and the markings thereon are strong and very well defined. The flowers are inevitably heavy in texture and they seem to open very wide most of the time. Segments are quite broad and we did not see one example of a feathery flower.
Colour is pretty constant across the Tableland. Normal colour is just like the example on page one of this website: See pic of var. blackdownense Bonza. That colour would be best called a strong cream verging on light yellow. Occasional specimens displayed some intensely strong yellows and golds. Breathtaking would be the best way to sum up these overtly bright colours.
Years ago I was given around a dozen pieces of var. blackdownense. When these flowered, a couple of white ones were amongst them. So naturally I figured that a few whites would be represented in the wild population as a whole. There was barely a specimen of var. blackdownense NOT flowering in 2012. Yet we did not see a single white form amongst the entire population on Blackdown. I have no hesitation in saying that white is a rare colour in var. blackdownense.
Lastly, it is the raceme that sets var. blackdownense apart from the other varieties. A big percentage have beautifully arranged rows of blooms. Occasionally a sparsely flowered brush of blooms was evident. Mostly they were what judges refer to as foxtails of closely arranged flowers but not overlapping. The flowers of the best of them however have the most incredible arrangements. Have a look at some of the pics I have put into the Gallery section of the main menu.
Not a lot of people have any experience with this variety of D. speciosum. There is a range of vegetative factors that stand out to the trained eye however. One must understand of course, that like D. speciosum everywhere, nothing is absolute.
The main thing that separates var. blackdownense from other varieties is the average size of the pseudobulbs in the wild populations. In general it is certainly a diminutive or stumpy grower. Bulbs around the size of a large banana are about as close as you can get to the average representative size. But there are certainly many larger examples to be seen. And some outlandish smaller ones are not uncommon.
I have seen some specimens with bulbs around 350mms long to the first leaf. Some of these are skinny and others as thick as your wrist. On the other side of the coin, I have seen plants with seed capsules on them where the seed capsule is actually larger then the bulb the raceme emerged from. If I showed you a picture of some of them, you would be forgiven by me if you guessed them to be var. pedunculatum plants.
When the new growths are on the way they are so very distinctive from any other variety. Until they mature they are quite literally purple or deep maroon in colour. As they mature the pigment turns to green and they end up as typical D. speciosum pseudobulbs and leaves in colour. No one can fathom the reason for this strange happening. But it is universal throughout the var. blackdownense population and the habit is maintained in cultivation, even after a decade or two.
Var. blackdownense is strictly a rock dweller. I have not seen a plant on a tree and have not heard of anyone reporting it as so. Over the vast majority of the Blackdown Tableland, var. blackdownense is the only epiphytic orchid to occur with the exception of a few odd specimens of Bulbophyllum minutissimum.
In one very deep, protected and isolated valley, there are also a few others species growing with the D. speciosum including D. tetragonum, B. schrillerianum and two small specimens of Sarchochilus hillii were seen as well. Also, Cymbidium canaliculatum is very sparingly observed despite it being highly visible in the lowlands surrounding the Tableland.
In the bush house this is one variety of D. speciosum that is shy to flower. It must receive strong light when new growths are coming or flowering eyes will not form in the leaf axils. And its safe to say that it takes the same bright light to inspire var. blackdownense into blooming. Always keep this in mind.
If you have limited space in your backyard then this is the speciosum for you. With var. blackdownense the flower shape is pretty much better on average then with most other varieties. And the colour range is enough to keep you guessing as well. Combine this with the absolutely superb arrangement of the flowers on the raceme and also the short stubby nature of the bulbs themselves and you are really looking at something special.
It surprises me that some of the seedlings I have available in the Seedling Catalogue did not sell with more gusto. I have used some absolutely magnificent var. blackdownense parents in two of the crosses and there are pictures of these in the Parents Gallery. I therefore assume that not a lot of growers are aware of what a joy this variety can be. From my perspective, I can announce right now that in the future I will be doing a lot more breeding with var. blackdownense . . . such is my faith in its ability to shape the future of D. speciosum breeding.