Pterostylis plumosa: Plumatochilos plumosum

plumatochilos-sp-woodland-sm
Plumatochilos sp Woodland

 

If you are out and about this week, keep an eye out for this attractive and unusual greenhood with its bottle brush labellum and rosette of “pineapple” like leaves.

Commonly known as Woodland Plumed or Bearded Greenhood, or Plumatochilos sp. Woodland Bearded Greenhood.  The reason for the phrase name is because many consider that it is a separate species, in this instance, from Plumatochilos plumosum (syn Pterostylis plumosa).  Originally all of the Bearded Greenhood were considered as one species – Pterostylis barbata but then Leo Cady named Pterostylis plumosa as a separate species.  David Jones in his 2006 tome listed four species, P. barbatum, P plumosum, P. tasmanicum and P. turfosum.

Here in South Australia, Bates lists P. tasmanicum and two with phrase names suggesting that they are distinct from P. plumosum.

Peter Fehre recently posted on the Tasmanian Native Orchids Facebook page some helpful hints differentiating between P. tasmanicum and P. plumosum.  Very similar information is found in Bates South Australia’s Native Orchids.  These differences are:

P. tasmanicum – a short plant: short flower stem (not more than 14 cms), short labellum (to 15mm) , short ovary; short blunted galea (hood) to 25mm.  It prefers damp, sandy areas and swamp margins.

P. plumosumhas length; long flower stem (10 – 30 cm), galea to 40mm with a long tip, long labellum (to 25mm).  It is a plant of the woodlands and forests growing on well drained soil.

The differences between the two phrase named species are more subtle

References:

R J Bates, 2011, South Australia’s Native Orchids DVD, NOSSA

D L Jones , 2006, A Complete Guide to Native Orchids of Australia

Orchid Hunter Visits Kuipto

The following video is by Orchid Hunter, Julian Pitcher.  Julian is concerned about the conservation of orchids and is also keen to teach others about Australia’s unique orchids.  At the time of the visit, Julian was resident in Victoria; now he resides in Queensland.  Enjoy an interstate visitor’s view of our beautiful orchids.

Morialta Orchids

100 years ago on 15 July 1915,  the state government declared Morialta a National Pleasure Resort.  The Friends of Black Hill and Morialta have been holding a series of public events to celebrate the Centenary of Morialta.  As part of the celebrations, the Native Orchid Society of South Australia has conducted some orchid walks in the park.

In 2004, an interim Flora Species List was produced by the then Department for Environment and Heritage and 39 orchid species were listed. It is an interim list and considering that the park is 5.33 square kilometres with a range of different habitats, it is possible that there are more species than originally listed.

One native species not included on the list is Caladenia latifolia but its presence is well known to members of the Native Orchid Society.  Unfortunately the South African weed orchid Disa bracteata (Monadenia bracteata) has also been found in the park.

In this video most of the shots have not been taken at Morialta but it does showcase some of the orchids that can be found in the park.

Moving Labellums

The following article titled Moving Lablellums written by Helen Lawrence is reproduced from the NOSSA Journal Volume 36 (1) February 2012

Labellums are fascinating. Well I think they are fascinating, especially the ones that move.

Bunochilus viriosus labellum down
Bunochilus viriosus with the labellum down

Why do these labellum move? You may have observed that the orchids which have labellums often have “hoods” and inside these “hoods” are the pollen. It is quite simple, the pollinator lands on the labellum, triggers it and is held captive by the labellum. As it struggles to free itself it pollinates the orchid. Clever, isn’t it?

Bunochilus viriosus labellum up
Bunochilus viriosus with the labellum up

So that these labellums can capture the insect they need to be sensitive. Consequently they can easily be “set off.” This can happen with of a gust of wind, or if the plant is in a pot, the labellum may trigger if the plant is moved/knocked.

It is easy to see these labellums as they move up into their “triggered position.” They move reasonably quickly, so the insect does not have time to respond.

However, how does the labellum return to its “normal” position? Does it slowly return to the position, or does it happen in a sudden movement in the same manner as when it is triggered?

One day when I was travelling in the car with a Pterostylis curta (Blunt Greenhood), I observed something very interesting. When I looked at the flower, the labellum was up, but then when I looked at it a minute or two later, the labellum was down. The labellum had to move quickly. However was it the bumps in the road which caused it to move? I had to find out.

I devised an experiment to satisfy my curiosity, and find out what these fascinating labellums actually do.

First I had to find an orchid with a labellum that could be triggered. I ended up using an Oligochaetochhilus bisetus (Two-bristle Greenhood).

Oligochaetochilus arenicola
Oligochaetochilus arenicola

Second I had found a good camera that could take high definition video. I placed it on a “tripod” (a pile of books).

So I had set up my apparatus, set the camera rolling, triggered the labellum, and left the room.

So what happened?

For the first six minutes after I had triggered the flowers nothing happened. There was no movement that I could see.

In the next five minutes, the labellums of the two flowers slowly moved downwards until they were half way down.

After twelve minutes of the flower being triggered, the labellum returned rapidly to its original position. This final stage of the labellum moving lasted for less than five seconds, and appeared to move at the same speed as when it was triggered.

So it looks like the labellum returns to it normal position first moving slowly and then in a rapid final movement which returns the labellum to its original position.

Urochilus sanguineus
Urochilus sanguineus

If I thought it would be that simple, I was mistaken.

As I briefly looked through the fifty minute video I took, I came upon something that made no sense to me.

A minute after the labellum had returned to its resting position, one of the labellums suddenly returned to its “triggered” position. What’s more, there was nothing in the room to trigger the labellum: no wind, no insects, and no people. So what triggered the flower?

I do not know. Six minutes after the labellum was triggered it returned to its original position, and then two minutes later the other flower’s labellum moved into the triggered position. The first flower was triggered again for no apparent reason at all, four minutes after the second flower was triggered and still remained up.

Once the labellums returned to their original position, there was no more movement.

Maybe triggering the labellum causes a chain reaction. Maybe the labellums periodically “trigger themselves.” Well, I can’t give you any answers, all I can tell you is that it looks like this is an example of how we barely know anything about these wild gems. They are beautiful but bizarre and of course fascinating!

After 7 minutes, just before the labellum moved
After 7 minutes, just before the labellum moved
After 12 minutes, labellum about to fall
After 12 minutes, labellum about to fall
After 13 minutes, labellum in original position
After 13 minutes, labellum in original position

 

 

 

 

 

 

 

 

 

 

 

As a 50 minute video is a bit long to watch, Helen has produced a four minute video, so watch and enjoy the music!

Australia’s Most Popular Orchid?

Australia has some of the most varied, if not the most varied, terrestrial orchids.  This variety is reflected in the words used in their commons names – spiders, hoods, moose, cowslip, mosquito, comb, fingers, fairies, bearded, ant, bird, frog, helmet, midge, shell, donkey, bulldogs, parsons, bunnies, daddy long-legs, hare, rabbit, onion, leek, gremlin, duck.  This list is from words used for describing just the South Australian orchids.  The other states particularly Western Australia have even more common descriptive names!

With such a variety is there a favourite one?  From the searches and questions that come to this site, it would have to be the Flying Duck Orchid.  This orchid never fails to amaze people with its resemblance to a duck in full flight.

It was no surprise than to discover that the winner for the Australian Orchid Foundation 2014 Essay titled Our Favourite Orchid featured the Flying Duck Orchid.

The essay began “It all started with the arrival of an email ……. click here to continue reading

And just a reminder, it is only ever found in the wild.  No-one has ever been able to grow one and it cannot be bought or sold!  But so that we can all enjoy them, here is a short video clip …..

caleana major
Ducks in full flight
11sm C major actual size
To get an idea of the size of this superb orchid, bring this image up to A4 paper size

 

 

 

 

 

 

 

 

 

 

ABC Gardening – Terrestrial Orchids

Back in 2013, Gardening Australia of the ABC produced a video featuring Helen Richards, a Victorian who has in-depth knowledge of growing terrestrial orchids.  Though Helen lives interstate and adaptions do need to be made for different locations and conditions, this video of her shadehouse is very instructive for any South Australian’s wanting to grow their own terrestrials.

Click here to view the video and read the text.

Pot of Thelymitra Kay Nesbitt Cultivar copy
Pot of Thelymitra ‘Kay Nesbitt’ cultivar
Pot of Arachnorchis argocalla
Pot of Arachnorchis argocalla
Pot of Caladenia latifolia cultivated by Les Nesbitt
Pot of Caladenia latifolia

Orchid Season

South Australia has some very interesting and unique orchids but it is not always possible see them  either because one cannot get out to see them or the season has been poor with inadequate rain at the right time.  So, one of NOSSA’s member has produced a video.  It starts in autumn and goes through to summer.

So sit back and enjoy ……

Orchid Etiquette – Tread Carefully

An important first lesson to learn when out orchid hunting is to watch where you put your feet.  In this video the Orchid Hunter explains the how and why for watching where you step.

Related Article

Protect Our Orchids – Stay On the Path

Orchid Walks at Mt Lofty Botanic Gardens

For the last couple of years, NOSSA has been conducting spring tours at the Mt Lofty Botanic Gardens, South Australia, showcasing our beautiful native orchids to visitors far and wide.  They have come from not only Adelaide but from interstate as well as overseas from such countries as America, Germany, England and many others.  If you are planning to be in Adelaide during spring, then consider joining one of our walks, but for those who cannot attend here is a video for you.  So watch and enjoy …….