Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Tuesday, August 17, 2010

Bunochilus tunstallii in Robertson

I can now confirm that I have seen Bunochilus tunstallii in Robertson. I have previously reported being shown this species of "Tall Greenhood" south-west from Nowra, by Alan Stephenson, the ANOS Illawarra Branch President, and the ANOS Australia Conservation Officer.

This week I went back to one of my favourite spots along the Belmore Falls Road, 5 Km south from Robertson. I was down in this patch of forest, to monitor an Orchid which I have known of for some 5 years, but which now has a very tall flower stem on it, for the first time. But it is still just in bud. In cool weather it can take weeks for an Orchid to open its flowers. I just need to keep checking it, now twice a week.

While I was there, it realised that there is a slight difference, in size and also in habitat preferences, between two groups of "Tall Greenhoods" (Bunochilus sp) growing in this 300 metre long Melaleuca thicket.

Down one end of the thicket, it is denser growth of these Melaleuca shrubs, and so the ground is more shaded (darker). It is also wetter, as the creek running through this thicket completely soaks the deep leaf litter on the ground, and after rain, it can remain permanently soggy for several weeks. That is the situation this August.

Up the top end of the thicket, the ground is drier, and there is more light. I would say it is still a densely shaded area - (compared to more typical Sandstone scrub).

In the top area, which I know quite well, there are many hundreds, if not thousands of the regular Tall Greenhood (the regular species of this area, I mean), Bunochilus longifolius.

But down in the wet area, where I have not noticed many of these Tall Greenhoods previously, I found quite a number - which surprised me. They were growing in this very heavy shade, and growing out of permanently wet soil. Not just moist soil - actually wet soil. In some cases, the plants are growing out of pools of water, albeit it temporary pools.

To me they looked like Bunochilus tunstallii.
These plants were consistently smaller in height, had a more pointed tip of the galea (the hood), with a slightly pink "nose" of the galea (hood). Their labellums are brownish, but not as genuinely dark as specimens of this species I have seen near Nowra. Note that the labellum has far less of the "bristle hairs" than the B. longifolius.

Bunochilus tunstallii on the left, and B. longifolius on the right.
Click on the image, to enlarge it.
Left: Note the browner labellum, with fewer bristle hairs (B. tunstallii)
Right: note the light cream coloured labellum with a dark line down the middle and also the obvious bristle hairs on the plant on the right
(B longifolius).

Once I checked my photos, I was pretty confident of the ID, and I checked it with the records from the RBG PlantNet site. They report: "Distribution and occurrence: Grows in moist areas of sclerophyll forest in coastal and near-coastal districts; south from Robertson."

There we go again - Robertson on the edge of the distribution of yet another species of plant. This so often happens here - either we are on the southern end of the range of more tropical plants (e.g., Pterostylis hildae ) or on the northern end of the range of cooler climate plants (as in this case).

Alan Stephenson, knows Bunochilus tunstallii well. He has confirmed the ID which I had suspected. So now I am happy to "claim" this species for my local list of Orchids.

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