Tag Archives: South Australia

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.

Arachnorchis tentaculata

Arachnorchis tentaculata

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.

Arachnorchis leptochila

Arachnorchis leptochila

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.

Arachnorchis rigida

 

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.

Herbarium

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.

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.

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.

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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

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:

100th post: Questions and Answers

Wow, 100 posts, and I was never keen on writing those English essays!  So as promised this post will be a Questions and Answer post, and thank you to everyone who submitted a questions.  They are good questions and I will try my best to answer them.

Do Australian Orchids have one season?

In Australia one or more orchid species will be flowering at any given time of the year.  Currently our summer orchids are in flower, although many of the summer orchids actually grow in swamps and thus are rare.

The moose orchid only grows in swamps in South Australia and flowers

The moose orchid only grows in swamps in South Australia and flowers between November to April

As I was curious as to the number of species flower per month, I took all the species that grow in South Australia and plotted them for each region.  In the northern parts of South Australia due to desert there are only one or two species present, which tend to flower in spring.  However in the southern, wetter regions, there is more likelihood of finding an orchid in flower any time of the year.  From the averages of all the regions it can be seen that the peak in the orchid season is at September to October (the beginning of Spring).

The number of species flowering per region

The number of species flowering per region – Click on image to enlarge

As a keen photographer, I would love to know – in a general sense – where you find a lot of your orchids?

Generally I don’t say where I find orchids partly because some of the sites that I visit are sensitive and it is not wise to have a large number of people visiting the locations.  Also with some of the rarer species, in particular the Duck Orchid, are prone to digging because people do not realize how difficult they are to grow.  No one, not even the experts have been able to grow it.  It is also illegal to take any plant (even picked flowers or capsules) from the wild without a licence.

The duck orchids can not be grown

The duck orchids can not be grown

However there are a lot of locations were you can find orchids.  Where there is native habitat in good condition, there should be orchids.  These include the Mt. Lofty Botanic Gardens (I was up there last Saturday and Dipodium are still flower – even some in bud!), Morialta Conservation Park (take the track on the left to the second falls as it has numerous winter/spring orchids growing along the edge), anywhere in Belair National Park which is a hive for orchids and actually has a few rarer species growing there.  There are many other locations in the Adelaide Hills where they can be found.  Pretty much it comes down to having quick eyes and knowing what habitat the different orchids like.  Anywhere where there are few weeds, there will generally be orchids growing.

A really good way to discover more locations and orchid species is to join an orchid club and go on an excursion with others.  I personally would recommend the Native Orchid Society of South Australia, but have I mentioned that I am their Assistant Editor?!

Arachnorchis tentaculata

The King Spider orchid – Arachnorchis tentaculata – found at Scott Creek Conservation Park

There has been a fire in the Belair National Park, is it likely that there will be a flush of orchids in the fire location come Winter/Spring?

Fire and orchids is such a complex topic.  For those who aren’t local there was a bush fire which occurred a couple of weeks ago in a national park pretty close to the city of Adelaide.  This coming season I would expect to see more orchids flower in that area, in particular the fire orchid.  I will be checking it out later this year to see what happens.  I’ve written about orchids and fire previously.

However there are long term effects of fire that are still being researched.  The following article is highly recommended reading:

Black Saturday Victoria 2009 – Natural values fire recovery program by Mike Duncan

Why some orchids have the trigger mechanism and some don’t?

What a lovely questions – I wish I knew the answer!  There are a number of species that have labellums that can move, from Pterostylis which flowers in the winter to the Duck Orchids which flower in late spring.  They all have different pollinators and the flowers look different.  The trigger mechanism is just one method for being pollinated.  Other orchids use different methods such as imitating a female insect or imitating another flower.  This article could be of interest:

Notes on the Anthecology of Pterostylis curta (Orchidaceae) by Peter Bernhardt

The labellum of the Bunochilus viriosous (also known as Pterostylis viriosous) can be triggered. Photographed in Hardy Scrub

The labellum of the Bunochilus viriosous (also known as Pterostylis viriosous) can be triggered.
Photographed in Hardy Scrub

What is the meaning of life?

The meaning of life is…             [unable to compute]

Thank you everyone for your questions.  I learnt a few things from writing this post and I hope you did to.  Orchids are so complex and amazing!

Victorian Orchids

South Australia is the only state in Australia that does not have any epiphytic orchids.  Our state is the driest state in Australia and does not have any rainforests that could offer a suitable condition for them.  So here is a video about some orchids that grow across the border in Victoria.