Tuesday, 20 August 2013

Local orchids oblige with familiar names

After much fuss and bother it seems that I only need to learn new names for two blue-flowered orchids around Melbourne. When I left for Sydney in 1998 the whole orchid world - if you lived in Australia - was about to be torn apart. Greenhoods and spider orchids (and, if you like that kind of thing, rock lilies) were the primary target with local taxonomists ready to rip into the genera Pterostylis and Caladenia (and Dendrobium...).

A couple of weekends ago Lynda and I revisited a few old orchid haunts on the outskirts of Melbourne - Professors Hill in Warrandyte, and St Helena Reserve up Eltham-Greensborough way.

Happily, in terms of me having to remember new names, I only have to remember that the blue-flowered spider orchids are Cyanicula rather than Caledenia. I had hoped to find two of them - Cyanicula caerulea and Cyanicula deformis in flower: according to my notes, twenty-two years ago, both were flowering at Professors Hill in August (in 1991).

As it turned out, nothing blue except a creeping glycine, which is not an orchid and more purple than blue anyway. My records also include a few greenhoods and helmet orchids. Happily these were  doing their thing. This is the local helmet orchid, Corybas incurvus with its slug-like flower.

No need to worry about new names, except that what I used to call Pterostylis longifolia is now Pterostylis melogramma. And the one of the more distinctive species hiding within this taxonomic group, with its stronghold in the Warrandyte-Greensborough area, had been already (in 1993) been named Pterostylis smaragdyna by Canberra botanists David Jones and Mark Clements.

David also called his dog at the time Smaragdyna if I remember correctly. But of more consequence, in the early 2000s he and Mark, and others in a rather complicated series of overlapping papers, proposed that Pterostylis be split into 16 genera. This wasn't widely accepted and by 2009 most people were back using Pterostylis for all the greenhoods.

It wasn't that these groups, or at least most of them, were well supported by DNA and more traditional characters, but that it wasn't necessary to recognise them at genus level - some are now used to divide the greenhoods into two subgenera and 10 sections but still calling them all Pterostylis.

So I can tell you these two are still Pterostylis nana and Pterostylis nutans and the species at the top of the post is the canine Pterostylis smaragdina. The next one is, I thought might have been Pterostylis melogramma, but it seems I'm a little rusty. My colleague Neville Walsh is punting for Pterostylis smaradgina again based on the way the flanges on the hood almost meet.

Anyone who has gone orchid hunting will know that in the absence of flowers one gets very excited about leaves, usually just one of them. In this case we found the long slim leaf of a sun orchid, Thelymitra, and the hairy leaf of a Caladenia, or perhaps Cyanicula.

Things could be worse with this latter one. The spider orchids were also ripped apart back in 2001, but again the consensus is that there was no need to take things that far. The blue-flowered ones had been segregated a year earlier into Cyanicula and that has stuck. The other five new genera - Petalochilus, Stegostyla, Arachnorchis, Drakonorchis and Jonesiopsis - are now a footnote in the story of Australian orchidology. I would say, however, that the footnotes accumulated over the last few decades make fascinating reading!

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