Gibbosas in flower now.

This morning I met up with Tony Rodgers, to show him some of the "Gibbosas" at Albion Park. Silly me, I parked in a slightly different place to normal, and spend 15 minutes wandering about before I found the right spot. That is good, for it means the chance of people finding these Orchids on a random basis is not very high. Lets keep it that way.

Judging by various comments and feedback about "lost sunglasses found at Kurnell" etc, it seems many people know where those other rare and localised Orchids are. Who knows when "many" is too many?

A nice flowering stem
of Oligochaetochilus gibbosus

I find these unusual "Greenhoods" fascinating.
The thick, fleshy labellum protrudes on a hinge.
They can snap shut if disturbed, by an insect
or a clumsy photographer.
Oligochaetochilus gibbosus

This plant has the"lateral sepals" deflexed
even more than normal.
Oligochaetochilus gibbosus

A lovely specimen
found away from the main colony.
Oligochaetochilus gibbosus

Close-up of the Labellum
of Oligochaetochilus gibbosus
Note the two stiff fibrous hairs

 The even better news is that we found a number of individual specimens of these Orchids away from the main colony. 

Leaf rosettes of Oligochaetochilus gibbosus
These non-flowering plants are already going brown.

"rufa Greenhoods" - another "first" for me

Today I went to Yalwal, south-west from Nowra, to a place where Alan Stephenson had showed me last autumn. The reason? To see the Oligochaetochilus rufus (otherwise known as Pterostylis rufa) which are to be found in this spot.

This is the first time I have seen this species, in flower.

When I first "got into" Orchids I became fascinated by the many shapes of Greenhoods, and then I discovered that some "greenhoods" were red. That's when I first realised the mystery of Greenhoods - which lay in front of me.

Regular readers will recall that I published a post about the "Gibbosa Greenhoods" several weeks ago. And then the related "bicolor Greenhood" the next day. Both those plants are related to this plant, which is the "nominate species" for what is known in Orchid circles as the "rufa group" of Greenhoods. Yet the similarities are not in colour (for both those two plants are green). No, the primary similarities lie in the shapes of their "labellums" and their dome-shaped "hood" (galea) and the wide flange under the galea which is nearly closed off. There are other factors, such as the leaf rosettes and the sheathing stem leaves. Anyway, that's all getting a bit technical - sorry.

To me, this is a very exciting "first" for me, because these plants are quite iconic for me, for the reasons given above. So lets look at the plants themselves.

Oligochaetochilus rufus - a profile view.
Note the deflexed lateral sepals underneath the hood.Here is a lovely plant with three flowers and several buds yet to open.
It is relatively tall for this species,
but it is still only about 6 inches high (12 cm approx).

Here is a lovely pair of plants growing in close proximity.
These were barely 4 inches high.
The open flowers were even lower than that (buds above yet to open).

Here is the most distinctive feature of this plant
- the labellum with stiff hairs.
These hairs are long, all around the sides and the lower edge.
There is a band of short stiff hairs across the upper edge of the labellum.

Here is the botanical illustration for this species from PlantNET.
Here is my best cropped image of the "labellum".
You can see how well drawn is the image above.
Here is another plant with the labellum having been triggered (closed).
You can see the yellow "hinge" of the labellum,
which is now closed right up inside the galea.
With the stiff hairs all around the labellum,
any insect which might have triggered the movement sensitive hairs
would be "imprisoned" inside the galea,
being unable to squeeze out past these stiff hairs.
The labellum relaxes and opens after some time, freeing any insect
which might have been trapped inside.
That is a technique designed to help the plant achieve pollination.

The "gibbosa" had a quite different shaped labellum.
It had only two of these long, stiff hairs.

"Gibbosa Greenhoods" in flower.

An orchid with the "barely possible to pronounce" name of Oligochaetochilus gibbosus is just coming into flower down at Albion Park. It used be called Pterostylis gibbosa. You could try calling it the Illawarra Rustyhood, but it is not reddish brown as one might assume from that name. Its enough to make one want to give up (but see below, for a little glimmer of understanding, based upon a search for the etymology of the name).

That's why I have referred to it simply as the "Gibbosa Greenhood" in the title of this Blog posting.

Note the prominent brownish labellum, with several (only) stiff hairs.
Presumably these hairs act as a movement detector,
to help trigger the Labellum to snap closed, when an insect is present.
(Click to enlarge the image).

Here it is with the Labellum snapped closed.
That is a pollination technique,
designed to trap an insect inside the "hood"
which is where the pollen grains and the stigma (female organ) are located.
This is the botanical illustration for this species, from PlantNET.

By the way, my favourite on-line dictionary - the Dictionary of Botanical Epithets reveals that "gibbosa" means "humped". It is a very useful reference site, which can help one make sense of strange sounding names.

As far as I can work out the "impossible sounding name" Oligochaetochilus refers to having a few (oligo) long flowing hairs (chaeton) - Gk. khaite "long flowing hair". That actually makes some sense, now that I have tracked back its compounded etymology.

This Orchid is known to occur in very few locations, and several are in restricted (privately owned) sites, which is probably just as well. This plant is classed as an endangered species.

In truth, it is pretty hard to find, growing amongst long Poa grasses in a large reserve at Albion Park, just down Macquarie Pass from Robertson.

I had been invited down to see the "Gibbosas" by Kirsten, a colleague from the Illawarra Branch of the Australasian Native Orchid Society. So I had the benefit of an expert local guide. Thanks Kirsten.

Anyway, we drove right to the spot, and examined some of the first Gibbosas, then went for a walk around the Reserve, to look at other plants (and Kirsten's favourite young Red-bellied Black Snake).

The next Orchid we found was a total surprise to both of us, the "Blue Caladenia", or as it is now known, Cyanicula caerulea. Hardly "sky blue" (its original Latin derivation) to my eyes, but very blue, none-the-less. These days it can mean "dark blue, or even sea-green" There is no green in the pigment of this flower. Blues and purples, yes, but no green tones.I have seen illustrations of this plant in many books, but I have never seen it myself before, so this was a thrill indeed. A solitary flower, with the hairy leaf lying flat on the ground.
I have posted a few images from yesterday's tour on my Facebook site gallery.

Tomorrow I shall show some of the other plants we found.