Hyacinth Orchid (Dipodium roseum)

To put you out of your misery, Dearest Reader, here is an unambiguously pale pink Hyacinth Orchid - Dipodium roseum (with very few tiny dots of dark colour - and no large spots at all).

OK the "misery" has been mostly mine - trying to sort out these confusing plants. But I acknowledge the assistance of Alan Stephenson in sorting out these plants. I take comfort from the fact that this species was only named as a separate species in 1991 (Jones and Clements). Prior to that, everybody must have been confused by these "look alike" Hyacinth Orchids.

These images were taken on 2 January 2010, the same day as the other similar species, shown yesterday.

First thing to note is the habitat - on the side of a sandstone hill, overlooking Mittagong, NSW. These plants were growing in a small area of the hill which was "burnt off" last year. Many Orchids respond well to fire. There were many plants in flower in a small area of just a few hectares which had been burnt. I did not see any in flower in other areas of the same hillside which had not been burnt.

Second point - steep hillside on sandstone, therefore - perfect drainage.

Third point - Eucalypt forest, with typical "Sydney Sandstone" flora - Eucalypts, Proteaceae (many genera) and Acacias, as well as many "Pea flowers" ("Eggs and Bacon" plants).

A view of a rainbow over Mittagong
looking between Mt Alexandra and Mt Gibraltar (across the valley floor)
Taken ahead of a rain squall on 10 July 2007.
Note the Eucalypt forest canopy and steep valley below.

Here is a flower stem

Another stem of flowers showing two flower ovaries already pollinated.This is the full frontal view of the flower.
To my eyes, this is the most natural colour rendition of the flower.
It is definitely a clear mid pink.
Note the almost total absence of "spots".
Contrast this with yesterday's image of D. punctatum.

To show you the difficulty I have in presenting consistent colour-density in images of these flowers here is the same flower, photographed in slightly different light (in sun, not full shade), and probably closer to the flash - hence more over-exposed..

There, you don't often get more honesty in a photographer than that!
This shot does reveal the "mohawk" arrangement
of the fibres on the labellum.
Dark pink upright hairs in the centre,
and light pink flat hairs on either side of the callus ridge.
Click to enlarge, to see those details.

Explanation of light problems:
Because my Macro Lens is old and half broken
and the built-in flash unit has given up the ghost completely,
I use a cheap "add-on" flash with no controls.
Hence my problem of not being able to control the light consistently.
For a reference point, contrast the skin colour of my fingers.
Same fingers, obviously.
I did try to adjust it in Photoshop, but without success.
I decided to publish the honest photograph instead
for the sake of the flower details that the image did show you accurately.


Now to the diagnostic points of identification.
Note the recurved tips of the petals and sepals, especially the lower ones.
Here is a high-angle view of the labellum of the flower.
This is a rear view of the flower.
Note the recurved tips of the petals and sepals.
There is some very minor flecking visible.
It is insignificant compared to the flecking on D. punctatum.
Here is an underneath view , to show the shape of the labellum.
At the risk of provoking comment on my poor colour/light control,
here is a nice shot of the fine parallel lines on the keel of the labellum.
It is a pretty image and it shows very clearly what I wish to illustrate,
which is the parallel indented lines on the labellum,
reminiscent of rich corduroy fabric.
Click on the image to enlarge it, and see what I mean.
You just need to make an allowance for the artificial light.
The flower is paler than it appears here.
By contrast, here is a link to the same pose of yesterday's specimen
of Dipodium punctatum.