Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Friday, April 15, 2011

A School of Prawn Orchids

What better to term to describe what we found today on a rocky hillside near Sassafras, than a "School of Prawn Orchids"?

You can see the origins of the name here
Crangonorchis pedoglossa - The Prawn Orchid.
It is in fact this species is an extreme form
of Greenhood Orchid.
Formerly known as Pterostylis pedoglossa.
The dorsal sepal is extended as a "nose",
(technically called a "filiform point")
and the two tips of the lateral sepals 
are also filiform.
They are usually erect, but some are reflexed.

 Here is the botanical illustration from PlantNET,
which shows pretty clearly the structure of the flower, 
just as you see it in the photo.
By way of preamble to this story I should say that the "we" refers to myself, Alan Stephenson and, for the first time, my Blogging colleague Martin Butterfield and his wife Frances. And a very pleasant day was had by all. The visit came about because I wanted to go to Sassafras to see these Prawn Orchids, which I first saw this time two years ago. And as Sassafras is about equidistant from Robertson and Bungendore, I asked Martin if he wished to join us. EDIT: Martin's write up of the trip is here.

These tiny Greenhoods are actually hard to find (at first). They were growing on a steep hillside, on shallow soil, mostly growing between and under low-growing heath sub-shrubs, or jammed in beside rocks.
Habitat shots courtesy of Alan Stephenson
Fortunately, I am not in any compromising positions
in these images, for I had been 
"inching along" these ledges,
and lying semi-prone across the bare rock faces,
while photographing the tiny Orchids.
They live amongst the small shrubs, 
just above each ledge.
Each ledge is about waist height, 
But it is on far too steep an angle
for safe walking.
But the flat section below each ledge
(where one walks)
is covered with loose ironstone pebbles
and large chips of flaked rock.
There is very little stable foothold.
Habitat A - looking north
 Habitat B - looking south (from just below the same ledge)

Once you get to where the Orchids are likely to be growing, and once recognise what you are looking for, you will realise, suddenly, there are lots of them around and about.

Here are two Prawn Orchids 
seemingly bowing to eachother.
Is this some weird Prawn Dance?
Crangonorchis pedoglossa - The Prawn Orchid
Here is the best group we found today.
There are 10 mature flowers in this image, 
but there are some 30 rosettes in this colony.
 A "school of Prawn Orchids"?
This is a loose group, within a narrow alleyway
between small dense shrubs.
Click to enlarge.

Martin was teasing me about not having seen me "getting down and dirty" (as I often complain about - on this Blog - having to do to photograph inside Orchid flowers. I said that these were just too short, and with the shape of the "hood and nose", it was barely possible to see anything anyway. However, I did find a few plants growing on a rock ledge where I could lie down on the rocks and approach the flowers from below. Then I gently pushed one flower backwards to look inside.

Surprise, surprise.

Not only was there a Midge inside the flower, but after developing the image tonight, I realised that there was a minute "flower spider" inside the hood, which had trapped the midge in its web. "S*ex and Death" is a perennial theme in the relationship between Orchids and insects.

Click to enlarge this next image to see the details.
Midge and tiny "Flower Spider" inside the Orchid flower.
The Midge has been snared in the web, 
so it is not sitting "naturally".
The bright line coming forward 
(from the left of the flower)
is the pointed "nose" of the Orchid,
which is the tip of the dorsal sepal .
You can also see a line of spider web 
in front of the flower.
The books refer to "Gnats" 
pollinating these Orchids,
Looks about right to me.

These are very small plants. 
The leaf rosette is smaller than a 5 cent coin.

We found a few other species of Orchids today, most of which I have shown in some form or other over the laast few weeks. The most notable were the Pharochilum daintreanum, of which we found many, in several different locations. We also saw Eriochilus petricola (on the rock shelves), Eriochilus cucculatus (flowers mostly finished, but some quite large leaves, which grow once the flowers have finished). Alan and I saw lots of Speculantha ventricosa earlier on in the morning, and later on, I found one solitary Speculantha of indeterminate species, on a great rock shelf on Twelve Mile Road (northern section) in the beginnings of the Budawangs. Unfortunately, the road was closed, at about the 15 Km mark, so we could not go as far out into the Budawangs as we had hoped.

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