Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Friday, October 23, 2009

Yellow "Donkey Orchids" - two species

Here are two species of Diuris, the popularly named Donkey Orchids. I have another one to come - a mauve Diuris - which I will publish in the next few days.

Basically, one is spotted on top of the dorsal sepal (the hood covering the centre of the flower) and it has plain yellow "ears" (the petals). The other is more or less golden, with few markings. Its dorsal sepal is very rounded, and the labellum is very deeply pleated (folded) leaving a very prominent ridge. Both have prominent, raised petals, known as "ears" - earning them the nick-name of Donkey Orchids.

The first one is Diuris sulphurea, known as the "Tiger Orchid" or the "Hornet Orchid". My Aussie Nature Blogging colleague, Gouldiae, in Gippsland, published an images of this same species yesterday. It is a wide-spread species. These plants are very common on shallow "black soil" over sandstone of Kangaloon, along the slashed fire-break beside Tourist Road.
Here is a high shot of the full flower head.
The Petals ("Ears") are swept back.
They are plain yellow on both sides
(unlike D. pardina I showed 10 days ago).
Here it is seen from the side view.
One of the two spots on the dorsal sepal is clearly visible.
The matching "dot" is on the other side, of course.
The stalks of the petals are relatively long and dark brown
(below where the petal "ear" becomes yellow).

This view shows the column deep within the flower.
The dorsal sepal is ridged.Click to see the full detail of the flower.
The flat plate inside is the front of the "column"
The dorsal sepals are slightly crossed in this specimen.

The second plant is one I saw in the Royal National Park, last week, in a sandstone heath area, approximately 3 Km past Audley Weir and the NPWS Office there. This species is Diuris aurea - one I have never seen before.

This image shows the labellum with a prominent ridge down the middle.
The rest of the flower is relatively plain.
So it is basically a yellow flower,
but it has prominent ears, which are more or less upright,
unlike the plain yellow Diuris chryseopsis I showed 11 days ago.
Here is the full view of the flower.
The dorsal sepals (the two bits below the flower)
are green, and not crossed over.
You can see that the labellum has two callus ridges,
beyond the main folded pleat in the labellum. They are outlined in brown.
In this image, which is taken from a slightly lower angle,
you can clearly see two small wings beside the column.
They are sticking upwards like two little hands.This is a cropped image of the labellum and the column.
You can see how the dorsal sepal is rounded,
(like an old-fashioned "bonnet" style of hat).
Here is a shot of the full head of flowers.


mick said...

Your photos are always beautiful and they also make me go back to my Native Plants book from this area. I have seen and photographed the diurus alba which occurs up in this area. However, it was a few years ago and I need to find more next season and try to get better photos. Most or all of the bush flowers are now finished as it has been so very dry for the last 3 months.

Junior Lepid said...

Hello Denis,

Another informative post - thank you.

I'm keeping my eye open for more Diuris. No luck since I found D. orientis.

There is so much to learn.

Denis Wilson said...

Thanks Mick.
You are too kind. My photos are adequate, and the plants are beautiful.
I have not ever seen D. alba. There are lots of them. People accuse David Jones of being a "splitter", but when you look in close detail, they really are all different.
Great plants.
I will publish my photos of the purple one tomorrow. That makes 5 species this season.
Now is the time to look for your white one.

Denis Wilson said...

I will post on the Purple one today - Diuris punctata. It is the season for them, now. It is said to be in the Grampians, but I know how big an area that is.
Nobody has laughed at my typo in the title - "Donkley Orchids". I only saw it when your comment came through. Ooops.

Anonymous said...

thank you Denis for posting these photos on your webpage. I live in Orange NSW and after all the rain we have had in 2010 there have been many native plants flowering. We have many Tiger Orchids flowering at this time of the year and your photos have enabled me to identify these orchids accurately. Thank you again.

Denis Wilson said...

Thanks for the positive news. Comments like that make the whole process of Nature Blogging worthwhile.
It has been a terrific season this spring. Many Orchids flowering prolifically. Some in places where they were not known to occur previously.