Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Wednesday, May 18, 2011

Diplodium longipetalum at Douglas Park

Today Alan Stephenson and I went north, to Douglas Park and Thirlmere Lakes, to check out some plants I have seen recently at those localities.

Firstly Alan wanted to see some Speculanthas (Tiny Greenhoods) which I had found last week which were unusually tall (for Speculanthas), with "bunched flowers" - flowers all close towards the top of the stems.These features are not necessarily unusual in Speculanthas, but these features are unusual in the only known species in the Douglas Park area. We decided they were worth checking out more closely.

These plants were growing in grey sandy soil,
over a rock ledge some 50 metres above the Nepean River, 
some 500 metres up river from the "Twin Bridges" at Douglas Park.
Speculantha species growing in shallow pocket of sand over sandstone rock.

A horizontal view of the same colony of flowers
Speculantha colony in sandy pocket on rock - seen horiontally.
Note the bunching of the flowers at top of the stems.
Most of the Speculanthas I find 
have flowers well spaced along the stems.
Speculantha species - note the thin stems and flowers bunched at top of stems.

This solitary flower shows clearly the tiny stem bracts.
The shot was taken in late afternoon light
with the sun shining through the flower.
Speculantha species - fine stem tiny stem bracts.
The shot was taken in late afternoon light
with the sun shining through the flower.
Speculantha sp. This flower is "past it" with the lateral sepals starting to collapse.
A fresh flower - quite pale.
Note the "points" of the petals wrapping over the dorsal sepal.
The galea has a noticeable "ledge".
From the side the flower resembles a question mark.
Speculantha sp. Douglas Park
Today I took this shot of a fresh flower,
The points of the petals are wrapped over the "hood".
The flower is very narrow (not bulging) at the base.
The labellum is protruding noticeably.
(That is an unusual feature in Speculanthas, for which 
the labellum is generally hidden within the flower).
The front of the flower is "overblown" with flash - sorry.
Alan is collecting a set of images of many different forms of Speculanthas. We both feel that the plants which we keep finding are not yet fully distinguishable, based upon the species which have been formally named as yet. That's why I am referring to these plants simply as "Speculantha sp. Douglas Park".

After having located these plants which I had found last weekend, we decided to explore the area for other interesting things.

We walked along a track running parallel to the Hume Highway. Alan found a rocky outcrop with a sheet of moss on it, and in the middle of that was a cluster of small Greenhood rosettes.
Rosettes of Greenhoods.
We looked around and found another colony of similar Greenhood rosettes and two plants with flowers. They had a beautiful shape, nicely rounded in the "hood" and a filiform point on the dorsal sepal.

I have to tell you that I was just getting into position to get a profile shot of the side of the first flower, to show the labellum - which was beautifully set. Alan moved in to line up to photograph the second flower. Suddenly he managed to dislodge a stick on the ground, which hit both plants simultaneously. Suddenly the labellum on both flowers, had snapped closed and disappeared from view (almost entirely). Here is the first plant, now triggered closed, with the fine pointed labellum just ever-so-slightly protruding.
To be fair, we have all accidentally triggered Greenhoods 
to close their labellums at times, 
but to trigger two to close at once requires talent.
I kept giving Alan heaps about that, 
during the subsequent walking and talking.

Diplodium longipetalum - a perfect flower. Labellum just protruding a tiny bit.
Having left the flowers alone, to see if they would re-set themselves (as they often do), we came back after about half an hour, and they were still "closed". 
Alan then redeemed himself, in my eyes, but using a fine twig to prise the labellum back its "set" position - fully protruding. Here is it - with the labellum reset by Alan.

So what species is it? The images which we took clearly matched the images of Diplodium longipetalum  also known as Pterostylis longipetala. This is yet another new species for me. And a lovely one it is, too.
Click to enlarge the image, 
to see the fine pointed labellum fully protruding.
Diplodium longipetalum - with Labellum in the "set" position.
 Here is one flower seen from above.
There is some brown colour on the hood.
One of the two points is facing forward, but
the fine "filiform" tip of the dorsal sepal is clearly visible from above.
Click to enlarge the image.
Diplodium longipetalum - seen from above.
 Here is the flower seen from the rear view.
Click to enlarge the image to see it properly.

I mentioned that we went to Thirlmere Lakes after Douglas Park. Unfortunately to recount our experiences there, would take too long for a single Blog posting, so I will hold that story over till next time.


Mr. Smiley said...

Nice stories Denis. Must be some varied pollinators for these small orchids. They are of different sizes so the pollinators must also be different. You would have to be very lucky to encounter them

Stewart M said...

Hi there - I have to say I find your knowledge of greenhoods remarkable! The first real post on my blog came about because I found some greenhoods growing in the nature strip at the bottom of my street. I felt good because I knew they were greenhood - but I have no idea what species! Next time I'll send some picture to you.

Makes me wonder how much money would flow towards Devil research if there was a sports team that used them as a logo that was more high profile than Tassie cricket. People would be falling over each other to give money!

Cheers - Stewart M - Melbourne.

Denis Wilson said...

Hi Stewart

It does seem odd that sucha n iconic animal is dying out for lack of funding of research.
Happy to assist in any way I can re Orchid IDs.
I am fortunate to have some good contacts who help me find plants, and help with IDs when I find them by myself.
My email is linked from my profile.