Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Sunday, January 03, 2010

Hyacinth Orchid - Dipodium punctatum

Sorry to go on and on about Hyacinth Orchids, but it is the season for them - they are popping up all over the sandstone plateaux of the Southern Highlands. And they are lovely, and showy, and best of all, highly visible. One can even spot these tall Orchids as one drives along a country road - that's pretty remarkable, compared with the normal difficulty in finding Orchids.

But, they have been causing me headaches, trying to sort out the various species, especially distinguishing this one from Dipodium roseum. (More about that tomorrow.)

I have gone back and "revised" and "re-revised" the names I have attributed to certain plants which I have published previously as Dipodium roseum. Wherever I have edited those earlier posts, that fact is made abundantly clear.

Ironically, today's post is about a most unusual form of Dipodium punctatum. These specimens (there were a few of them, not just one aberrant specimen) had green stems, instead of the normal dark red-brown stems.

But I have struggled to identify these plants positively - mostly because there are many much more strongly coloured forms which other people have published on their Flickr Sites and specialist Orchid Websites.Trouble is, many of the Flickr images are nice photos, but incorrectly identified.

My problem is that this what the local (NSW Southern Highlands) plants look like. But, none-the-less, although they are not as strongly marked as many plants are (from other areas) I have little doubt about their identity for several reasons - which shall become clear in the course of examining these images.

Here is a single flower - showing its heavy spotting.The first thing I noticed about these plants (there were two growing close together) was the pale buds at the top of the stems. And the stems were greenish yellow, not dark red-brown. I have never seen such a form before.
At first I thought it must be Dipodium variegatum, but that plant has spots on the pedicel and the ovary (the individual flower stem and the swollen base of the flower). These plants do not. (Click on the hot link here to see my previous post about D. variegatum.)
Here is a closer view of the pale buds.
There were many black ants on the flowers,
but they were a larger species than tiny house ants.
They were approx 8mm long.
Note how the top buds are yellow with dark spots
but as the flowers mature, they achieve a mid-pink colour,
but still with dark spots.
And closer still.
Note also there is one flower visible from the adjacent plant
(of the same variety).
Note its true pink colour, with dark pink spots.
Here is the full image of the two plants -
both with greenish yellow stems..
Here is a close-up of the base of the two greenish-yellow stems.
The rear view of the flower shows how heavily spotted it is,
especially on the lower parts of the flower.
In this side view, one can see that the petals and sepals of the flower are not recurved. That is one of the diagnostic points which David Jones stresses with regard to Dipodium punctatum.Here is the labellum of this flower - as seen looking down directly from above, to show the shape of the labellum, and the fine fibres on the central section of the labellum, and the grooved lines along the labellum.Alan Stephenson, the Conservation Officer of the Australasian Native Orchid Society, to whom I have sent these images, has now confirmed these plants as Dipodium punctatum. Many thanks, Alan.

4 comments:

mick said...

Beautiful flowers. Once again I am sure that I have seen one similar to this - but at a very different time of the year. I need to keep a much more careful calendar of when I see flowers. I do keep such a list for birds - but haven't been so careful for flowers.

Denis Wilson said...

Hi Mick
Your plant is very likely to be
Dipodium variegatum which is much more strongly marked and which grows strongly in coastal sandy forests. It also is said to flower from August to February. Much earlier than the others. Add in your northern position, that makes sense.
.
It does occur in southern Qld.
.
It has dark red dots on a white background (not pink). If you ever see them again (next season), check the stem of the individual flower.
.
This species has dots on that stem (the pedicel) and has a green flower stalk (the main stem), not black/red like most of the other species do.
My one today was an exception (with a greenish yellow stem).
.
Really bright cheery flowers. they always, make me happy.
But I associate them with high summer and Christmas and New Year, of course.
.
Cheers
Denis

Alison & Glen said...

I just found 2 plants growing on a steep hillside overlooking a creek flowing into the Queanbeyan River, near Googong Dam. Have walked in this area extensively for 20 odd years & never seen them before - must be the wet season. Just stunning!
Alison Crawley

Denis Wilson said...

Hi Alison
Glad you have found the Hyacinth Orchids. They are stunning things.
Strange lifestyle - no chlorophyll (well in the case of those plants, probably some, but not much).
Given the locality where you saw them, probably Dipodium roseum - but the differences are very slight.
I was out this morning photographing some more, out in the Southern Highlands. Great season for them, as you have noted.
Cheers
Denis