Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Sunday, September 27, 2009

Two species of Glossodia (Waxlip Orchids)

Here are images of the Small Waxlip Orchid (Glossodia minor), and the more familiar large Waxlip Orchid (Glossodia major). One is a size comparison image of both species - with my fingers as the scale bar.

Firstly, let me say that it has been a very dry spring this year, in Kangaloon (near Robertson) where most of these images were taken. As a result, these Small Waxlip Orchids were very small (even for this species). They were growing in nearly bare patches of ground, in very poor yellowish clay soil, over sandstone. The trees nearby are mostly Scribbly Gums - which tells you something of the poor soil quality. The Orchid stems were less than 2 inches (50mm approx) tall. These Orchids make the small "Dusky Finger" Orchids I have shown recently, to seem "tall" by comparison. Their flowers are a little larger (wider) but they are still small plants.
Here is a macro image, to show the detail of the flower.
Click to enlarge to see the pair of "dog's ball" glands on the labellum.
Pardon the crude reference, but these paired glands are very distinctive.
Here is the first of the two finger scale images.
Here, for comparison is Glossodia major
with the same two fingers for scale.
Here is the composite image of the two species, with my fingers for scale. If anything, the image on the right is still slightly larger than it ought be
- as you can judge by the finger comparisons.
This is as close to real size as I can manage.
You can see that the Glossodia major is approximately 50% larger than
its smaller cousin.
The colour difference is real, not apparent,
as can also be judged by my fingers.
Glossodia major is clearly more blue,
whereas Glossodia minor is much more purplish.
*****
Finally, for a further comparison of the difference in these species here is another image of the labellum and column of Glossodia major.
Contrast those internal structures with the first image (above).
This was taken at Black Mountain (Canberra).
This image is deliberately taken nearly at ground level, to see the flower, from an insect's eye level, and to show the "active" parts of the flower
- the column and the cover over the pollinia.
Note how "hairy" the stem is on this species (click to enlarge).
*****
I will repeat a point I made a few days ago, that any beauty we see in these Orchid flowers is purely incidental to the function of the flower - which is to achieve pollination. As the normal pollinators of Orchids are insects, I usually try to take an "insect's eye" shot of these flowers.

2 comments:

Miss Eagle said...

Wonderful picture of rosella at the top of the blog, Denis. Love it. Would make a lovely Christmas present for someone.

Blessings and bliss
Brigid

Denis Wilson said...

Thanks Brigid
I like the Rosella too, which is sort of obvious, I guess.
Cheers
Denis