Spiders

One aspect which makes orchid really appealing is their variety and beauty.  They are stunning pieces of artwork.  Here are some photographs of some of the spider orchids (Arachnorchis) that grow in South Australia.

The most common spider orchid is the King Spider Orchid, Arachnorchis tentaculata.  It is a stunning orchid, and one of the larger ones, being up to 10 cm across.

The Queen Spider orchid, Arachnorchis leptochila, is not as common in South Australia.  It is smaller than its sister, and has a more rigid flower.

There are many other spider orchids, but one of my favourite ones would have to be  Arachnorchis rigida.  It’s white petals are so crisp.  This is also quite a small flower.

 

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Four years

So it has now been four years since I have been observing this patch of helmet orchids (Corysanthes diemenica).  The first time I saw it in 2011 was probably the best year.  This year was not brilliant but it looked fairly good.  2013 was probably when I saw the least number of orchids flowering.

In 2011 I saw the most flowers in this patch.

In 2012, there were not many flowers out and is probably the least number of flowers I’ve seen at this patch.

In 2013, there were not many flowers but a lot of leaves were up.

So 2014 put in a fairly decent display.  A lot of the plants that were up were flowering.

And here is a picture of the little helmet orchids (taken on my phone) when the sun decided to come out!

Greenhoods

I haven’t written for a while due to a very busy schedule and unfortunately have not been able  to see many orchids.  It’s very nice to see that I’ve reached 400 followers – which is a lot of people – thank you!  Yesterday, if you were following me on Twitter (@OrchidNotes) it would have been pretty easy to see that I was out orchid hunting.  The major find was the Diplodium robustum.

There was this lovely patch of orchids with over a couple hundre of orchids in flower and many more plants in leaf.  It was a very spectacular display.

Two flowers with the rest in the background

A cluster of flowers

A bud on the left and a flower on the right

Looking into the flower and being able to see the labellum and column

All these pictures were taken on my phone (Samsung Galaxy S4).  When I arrived home all the pictures I had taken are automatically uploaded to Google Images.  What was a surprise was that Google went through my pictures and picked the following as my best pictures from the day and then edited them for me!

It was fun to get out and see these wonderful orchids.  Have you been seeing any orchids recently?

Winter at Mt Crawford Forest

To those who have visited the Mt Crawford area from Adelaide are usually left with an impression of an area that is noticeably colder and wetter.  I have had the pleasure of working in the area in the last couple of months and this impression has been reinforced, especially after getting drenched in heavy rain at my last visit.

I took a picture with my mobile telephone showing the mist around us as we worked.  We were above the cloud base on the edge of a sandstone ridge.  It is easy to keep warm climbing up and down a slope like this.  We were removing feral pines that originated from the adjacent commercial pine plantations and you may be able to see one lying on the left of this image.

On a sunnier day earlier in the month I found a pair of flowers of Diplodium robustum, the Large or Common Shell Orchid.  These were on the ridge next to the Heysen Trail.  These, I am told, are taller than usual for the species and resemble a form that occurs in areas of mallee.

From the back the flowers are strongly striped with green and white.  These flowers were facing south.  Elsewhere there was a colony of about 300 plants with over 30 in flower or bud; the majority of these faced up the slope.  This appears to be a strategy to make it more likely for the flowers to be visited by the insect pollinators.  The pollinators are small insects called fungus gnats, which look like small mosquitoes and don’t eat at all in their adult stage.  Only the males are pollinators and they need to be large enough to trigger the labellum inside the hood of the orchid.

At the base of the two flowers I found these little rosette.  This, surprisingly, is the same species.  This plant will not flower this year; it is preparing to flower in a future year.  There is a smaller flower in the lower left of this picture that I did not notice until I started writing this post.  It looks like a bud almost finished forming.

Orchids are not the only interesting flowers.  This is one of my favourite lilies – Wurmbea latifolia ssp. vanessae (Broad-leaf Nancy).  This is a female plant with the dark ovaries seen in the middle of the flower.  The flowers are white with rich, hot pink colours near the centre.  This was the first one I found on the 7th of June.  By the 20th they were easy to find.  I am told that the peak of flowering is mid-July and that earlier flowering this year is a result of climate change.

I am looking forward to visiting the area next weekend and taking more photographs, if the wintery weather lets us.

Mayfly Mystery

The Mayfly Orchid is a small orchid with very dark reddish brown flowers with long, hair-like sepals.  It flowers from late July to August.  One might question what sort of insect was behind the naming of this orchid, which does not even flower in May.  Mayflies are an insect with which many of us are not acquainted.

Close view of a typical flowering Mayfly Orchid

One source attributed the naming or the orchid being similar to the long legs of a Mayfly.  However, a quick search in the Internet revealed that Mayflies have fairly short legs, as in the image below:

Mayflies have relatively short legs … Source: http://www.empirepestcontrol.co.uk/wp-content/uploads/ephemerella_subvaria.jpg

It turns out that it is the appendages on the end of the abdomen that the sepals of the Mayfly Orchid resemble.  Mayflies usually have three tails (two cerci, one middle filament), although the middle tail is rarely reduced or absent.  All the tails are longer than the body, thread-like and similar in size.  Thus the three tails correspond with the three long sepals of the Mayfly Orchid flowers.

Source: http://australianmuseum.net.au/image/Mayfly

This is only half of the story; mayflies occur in swarms and these resemble colonies of Mayfly Orchids.

A colony of Mayfly Orchids in the Adelaide hills

Mayflies are a sign of summer in parts of the United States of America Source: http://www.severnsound.ca/SSEA_Mayflies.htm

Adult Mayflies are short-lived.  Most live for one or two days, but some for only a few minutes.  They form mating swarms.  Some swarms are quite impressive, even on Doppler weather radar.

So you may want to keep a lookout for colonies of Mayfly Orchids in August and see if you can imagine a swarm of insects with three long tails on their abdomens.

From the past – to the future

Recently I had the opportunity to participate in a tour of the State Herbarium of South Australia as part of the Open House Adelaide 2014.  Several years ago I had done volunteer work filing specimens away, so I was somewhat aware of how it runs.  However I did learn a few things from this experience.

The Herbarium lives in the first tram barn in Adelaide.

The herbarium houses over 1.2 million specimens, from species that have been collected within Australia as well as some specimens that are currently on loan from other herbariums in Australia and overseas.  There are also duplicate specimens from overseas in case they are lost in their country of origin.  These specimens are mounted on paper and stored in boxes within the vaults.

In the vault

An example of the boxes which contain the specimens

The important function of a herbarium is that they control the naming of new species.  In the collection there are type specimens.  These are the original specimen that was used for naming a species and thus will have all the distinctive features of that species.

Specimen mounted on paper

Some lichen

Another aspect of the herbarium is that they contain specimens that are have been collected from over 200 years ago.  In a display cabinet, they had some specimens that were collected by Robert Brown who accompanied Matthew Flinders in 1802.  These specimens were then transported back to England before they finally make their way back home .  It is incredible that they are still around, because back in the 1800s herbariums did not exist as we know them now.  The amazing part of this is that the really old specimens don’t look that much older than the specimens that were collected within the last few years.

Some original specimens collected in February and March of 1802

One of the problems that the herbariums face is a little beetle which seems to thrive on the dead plant specimens.  To prevent the spread of the beetle , the herbarium has in place some strict quarantine processes.  Before a specimen can enter the vault, it must be placed in the freezer for at least a week.  Also staff are encouraged not to take in any unnecessary items into the vaults.  This can make it quite a hassle when transporting plants between the herbariums.  To reduce this, they have recently established a database called Australia’s Virtual Herbarium with high resolution images of the type specimens that anyone can view.

When I was on the tour I asked if I could see the orchids which are kept in alcohol.  I was taken to a small room full of tiny little bottles with orchids.  They had lost their colouring but it was possible to see the 3d structure of the flowers – something that is lost in a pressed specimen.

Some of the orchids preserved in small bottles of alcohol

Here is a comparison of the specimen in the herbarium and a species in the wild.  Most of these specimens were collected in the 1960s.

If you would like to know some more about the South Australian State Herbarium or some of their resources, check out the following links:

• Know Our Plants: for the friends of the State Herbarium of South Australia
• Government website for the Herbarium
• eFlora of South Australia
• Australia’s Virtual Herbarium

Orchids and Fire

Many fires in Australia have caused harm and resulted in huge costs. There have be several major cases of fires causes sever damage and fatalities, including Ash Wednesday in 1980s in South Australia and Black Saturday in Victoria, 2009.

Image Source

However there are several orchids that thrive following a summer fire.  These include the black fire orchid (Pyrorchis nigricans), the rabbit ears orchid (Leptoceras menziesii), and the leek orchid (Prasophyllum elatum).  Let me make it clear, they need a summer burn.  In Australia we have a fire season during summer, when no controlled burns are allowed.  Sadly this is when the orchids need the fire, so it is generally the accidental fires or arson which provide the right conditions.  During the autumn and winter months, controlled burns are conducted to prevent the bushland becoming a fire hazard in summer.  Yet these burns often occur just as the orchids are emerging, and can kill the plants.

The black fire orchid, Pyrorchis nigricans, as its name suggests, appears to benefit from a summer burn.  Its leaves are very common, and can grow up to a 5cm across (which is enormous for an Australian terrestrial orchid!).  They usually need fire to flower.

A typical flower after fire

After flowering, the whole plant turns black, hence its name, the black fire orchid.  This picture was taken in summer.

The Rabbit Ears Orchid, Leptoceras menziesii, seems to flower better after a fire.  Below is a lovely patch that my father found following an a fire.  Unfortunately I did not get to see the patch, and have only seen a couple of flowers at a time.

One of my favourite orchids after flower would have to be the leek orchid, Prasophyllum elatum.  For this genus, generally the flowers and stems are green, but after fire, the flowers and stems turn black.  They look like black twigs sticking up out of the ground, so blend in quite well with their surroundings.

Without fire

A lovely tall specimen in a burnt area

Striking colours after fire

… and Dad, thanks for the pictures! 😉