Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Thursday, July 03, 2008

Pterostylis nutans starting to flower in Kangaloon

The cheery little Nodding Greenhoods (Pterostylis nutans) have started to flower, along Tourist Road, in Kangaloon. This is the botanical illustration which appears on the PlantNET site, linked above. I only know of one single colony of these plants here, which is odd, as the road runs for about 15 kilometres through the forests of Kangaloon and East Kangaloon. However when I checked for them today, the flowers were just starting. This photo below has been rotated to match, as closely as possible the botanical illustration. The underside of the "Labellum" is very visible, with hairy bristles on the "upper" side, and a clear brown line on the "underside".
Below you can see the way the plant actually holds its flower - hence its common name (and scientific name for that matter) - nodding. The tongue ("Labellum") is visible protruding in a reflexed position between the forked sinus (in the "underside" of the flower). Of course, with the angle at which the plant holds its flower, the tongue is pointing back towards the stem - but it is "underneath" the flower, in botanical terms.In this photo, the labellum has been "triggered" (yes, I admit I touched it) and the movement sensitive labellum withdrew inside the flower. (Compare the photo above and then the one below). This is what the flower does normally, in response to pollinating insects (and photographers fingers, it seems). As the green hood of the flower is almost transparent, you can see the yellow pollinia still inside the flower (on the far left of the image). So I know that this plant has not yet been visited by a pollinating insect (which if it had been trapped inside the flower by the labellum closing like this) would have been dobbed with the sticky pollen grains. A virgin flower.Here is a fresh bud, just forming. Interestingly, the newly formed bud is not yet bent over. It is surprising to me that the brownish colour in the tip of the flower is clearly visible, even at this early stage of development.
By contrast, this bud which is mostly developed, is clearly bent over, in the way the adult flower is held. The sinus is not yet developed, but you can see the swelling underneath the flower, where the petals separate and form the two "points" which dominate the shape of the flower once it is fully opened. I really like this photograph.
For more photos of this interesting little Greenhood, on my colleague Colin Rowan's Retired Aussies website, go to Victorian Native Orchids firstly, then go to the Pterostylis group of plants, and then go to Pterostylis nutans. Colin and Mischa have a great collection of photos, especially of Orchids.


mick said...

Great photos and I enjoyed your comments and explanations.

Denis Wilson said...

Thanks Mick
You have a nice blog too.

Sandy Straits and Beyond
We Aussie nature Bloggers should get together somehow. I will put up a link to your site, on the side bar of my blog, along with others I have met up with.

Duncan said...

Excellent photos and description Denis. You are a bit ahead of us down here in chilly Vic, I've only found two greenhoods so far, one nutans and one concinna. A good suggestion of Mick's I have both of you in my Aussie links, and will be adding more as they come to light. It's great to see Aussie nature blogs proliferating.