Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Saturday, March 30, 2013

Acianthella Orchids found at Gerroa.- update - Identity confirmed

A contact of Alan Stephenson's, Matthew, first discovered these plants last year, while working on "bush regen" work in the sand dunes in the Littoral Forest at Gerroa. Alan and I saw some of these plants last year, but the flowers had finished. I reported on the plants, with seed capsules present, on 15 June last year (much later than this year). That tells you something about the strange seasons we have been experiencing over the last few years.

Matthew contacted Alan yesterday to say that they were in flower again, (in fact mostly they had finished). But we went there today, met Matthew and took some photos of a few open flowers.

Front on view of Acianthella at Gerroa today.
Side on view of the Acianthella flower at Gerroa
The flower structure is clearly similar to
Acianthus exsertus
The whole plant is only about 2 inches high (about 50 mm) and the flower is less than 3mm across (slightly larger than a match-head). The front-on image when viewed at maximum pixels (as uploaded here) is about 50 times larger than the original flower.

That cropped image allows one to see the fine details of the flower, which is green except for the slightly rude looking pink cap of the anther (the male reproductive part of the flower). There is nothing subtle about Orchids!

These plants are presumably self-pollinating (at least David Jones's Big Book says so).

Plants growing in leaf litter on Littoral Sand Dunes
(2 plants circled in red)
Click to enlarge.

The shot of 2 plants growing amongst the leaf litter (circled in red) shows them at more or less real size (if viewed at full pixel size), if you are viewing this on a computer (smaller if seen on an I Pad).

The side-on view shows more clearly the structure of the flower which is clearly closely related to the more familiar Acianthus exsertus . The leaves are different though, much softer and not reddish underneath, and shaped almost like a "Club" (as in a pack of playing cards). The leaves are held above the ground (as is Acianthus). 
The tiny size of the flower is what surprised me most. At least Acianthus can be clearly examined with an un-aided eye. Not so these things. I had to use the camera, take a shot and then examine the image, to know if the flower was even properly open.

On the balance of probabilities, these plants are likely to be Acianthella amplexicaulis. I say this as, despite the difference in geographical range from what has previously been reported for that species, the photos I took look very similar to the ones Colin and Mischa Rowan have photographed. But their website does not show a location for their plants.

In that case this is still an important records, as a major extension of range - as previous records apparently are all north from the Hawkesbury estuary.
Thanks to Matthew and Alan for showing me these plants.


UPDATE 10 April 2013

Alan Stephenson has advised:

Have just spoken with Mark Clements and the orchid is definitely Acianthella amplexicaulis. This means it is not a new species but an extension of range of about 250 km and Mark was very pleased to get the samples. 
Thanks to Mathew for the find, as it is important.



That confirms my impression of the similarity of my images of these Orchids with those of Colin and Mischa, and of Bruce.

Good to have the ID confirmed, none-the-less, given the extension of range involved.

Once again, good work by Matthew in spotting these tiny things in the first place and in reporting them to Alan Stephenson. Thanks also to Mark Clements for the positive ID of the specimens.

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