Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Thursday, March 19, 2009

Corunastylis oligantha - yet another Midge Orchid.

Here is the second Midge Orchid which Alan Stephenson showed Mischa, Colin and myself last week. I was interested to see this one, because it is the true Corunastylis oligantha, not the plant which I had tentatively identified as that species, (last year). That plant turned out to be the closely related Corunastylis sagittifera. This plant is named correctly (here).

The first thing I noticed about these plants was their dark green lateral sepals. You can also see clearly the prominent hairs on the sides of the up-turned labellum of the flower on the lower right of the image. (Click to enlarge).
This is a fairly dark image, but it accurately shows the colours of these flowers.This is a brighter image, to help you see the details of the flowers.
This image shows how flexible these plants are (contrasted to the "Brittle Midge Orchid" I showed you yesterday). This flower stem had been bent over by a person or an animal disturbing it some time back. The stem stayed alive, and then the flowers emerged through the centre of the leaf (as they do), and then just the last part of the flower stem straightened up to hold the flowers vertically. The fleshy stemmed plant from yesterday was inclined to break off, if treated as this plant has been treated (naturally) - probably about 2 weeks before.
The black material in the background is a shallow moss bed growing over a sandstone rock shelf. The weather in February was very harsh, with several very hot, dry, windy days. The moss beds in much of the sandstone rock shelves in the Southern Highlands and down in the Shoalhaven area suffered like this. the moss has gone black, but I am sure it will recover. But surprisingly, these small and seemingly delicate Orchids have survived, to flower successfully. Obviously they are tougher than they look. Also, of course, they are adapted to the climate, and their delicate tissues are underground during the worst of the summer, and then the flowers pop up in early autumn, after the worst of the heat has passed. A good survival strategy.
Click to enlarge the next image.
There are some 15 plants of Corunastylis oligantha
growing in this small area of a moss bed.
This gives you an idea of how hard it is to spot these plants, even when they are in flower. When they are not in flower, it is almost impossible to find them. Incidentally, I do not know what the bright yellow plant in the centre left of the image is, but it is not an Orchid. Look for tiny little straight stems, with tiny flower heads on top of them, growing right at the front edge of the moss bed. Those are the Midge Orchids. Once you spot them, look for others further back.


Tyto Tony said...

Little wonder most native bees are so tiny, but I suppose other flying insects are also pollinators?

Denis Wilson said...

Hi Tony
Interesting point your raise.
Apparently this family of Orchids are pollinated by little Vinegar Flies, especially those species which have strongly scented flowers.
Some are believed to be self-pollinating.
That is a process which I cannot follow (personally), for we are so accustomed to the idea of improving genetic diversity, through fertilisation from another individual.
Many other Orchids are pollinated by Fungus Gnats, some by Wasps, some tiny ones by ants, and larger ones by bees, (native bees often).
In many cases the pollinators are very specific, and the plants have adapted to produce specific aromas which attract a particular insect. It is all subject to very intricate research by entomologists, botanists and bio-chemists (who synthesize the chemical attractors). Amazing stuff.

Anonymous said...

Hi Denis,

What fascinating plants these midge orchids are - amazing that they can survive and produce such delicate flowers in such harsh conditions. The last photo helped to put their size into perspective.


Denis Wilson said...

Hi Barbara
I was reluctant to post a photo of blackened moss, with some tiny spikes of nearly invisible Orchids on the moss. But you got the point.
You obviously opened the image to full res, and had a good look.
These little Orchids are numerous (in species) and widespread, but they have a preference for dry rocky areas, but they are seldom seen, except by Orchid enthusiasts. I guess that you wouldn't get them in your rainforest. To be honest I haven't checked, but that's my guess.