Monthly Archives: October 2012

Orchids of the Mount Lofty Botanic Gardens

Australia is a rich resource for orchids, especially terrestrial orchids which make up 82 percent of all the Australian orchids.  Terrestrial Orchids are found, mainly below the tropics in grasslands, heath lands, and eucalyptus forests.  Many are deciduous coming up in autumn/winter, flowering in winter/spring and dying down in summer.  Most rely on fungi to survive, and for germinated to occur.

What makes an orchid?

Orchids are always made up of five main segments: a labellum, column, two sepals and a dorsal sepal and two petals.

How do orchids reproduce?

Most orchids need to be pollinated by native bees, wasps and sometimes ants.  The introduced European Bee, because of its size, does not pollinate the flower, but can instead damage or destroy it.  Some orchids do not require a pollinator and are thus called self pollinating.

Orchids in South Australia

There are many different orchids; in fact, South Australia is home to over three hundred different species, some of which are yet to be described.  The Mount Lofty Botanic Gardens yields a variety of orchids, which will be covered in this leaflet.

Arachnorchis tentaculata King Spider Orchid

This species is relatively common in the Mt. Lofty Ranges, with flowers reaching ten centimetres across.  It can easily be distinguished by clubs on the end of its petals and sepals.

Diuris pardina Spotted Donkey Orchid

This attractive flower is distinguished by the spots on its sepals and labellum.  It received its common name as its petals reminded the English settlers of donkey ears.

Diuris orientis Wallflower Donkey Orchid

This distinctive orchid can be distinguished by its bright colours and particularly its labellum, which can be a shade of deep purple.  This species is also referred to as the Bulldog Orchid.

Diuris orientis x pardina Pioneer Donkey Orchid

It is not unusual to find hybrids of the donkey orchid.  It is often between these two species and can sometimes be difficult to distinguish from Diuris pardina.

Glossodia major Cockatoo Orchid

This purple flower is often found in fields, and is very common in the Mount Lofty Ranges.  It does vary in colour from purple to a pure white, with the different varieties growing together.

Pterostylis pedunculata Greenhood

This winter flowering orchid is often found in dense colonies which can number over a hundred plants.  It can be found in early spring in the Mt. Lofty Botanic Gardens.

Microtis arenaria Onion Orchid

This green flower breaks out of its cylindrical leaf.  Many people find the Microtis family difficult to identify due to its minute size.

Thelymitra rubra Sun Orchid

This pink sun orchid is one of three pink sun orchids.  It can be distinguished by the tufts on the top of the column.  It opens freely on warm days, when the temperature is over 25 degrees centigrade.

Thelymitra brevifolia Pepper Top Sun Orchid

This sun orchid has a distinctive red top on its column.  It can also be distinguished by red edges on its short broad leaf.  Its flower is smaller than Thelymitra rubra.

Thelymitra parviflora Sun Orchid

This common sun orchid has a blue flower and can be confused with a number of other blue sun orchids.  Like all sun orchids, it only opens on warm days, as this is when the pollinators are present.

There are many other types of orchids not considered in this leaflet.  However some field guides on orchids will enable identification of orchids which can be found in other parks and reserves around Adelaide or beyond.

Protecting Orchids

It is always a pleasure to find orchids but they do need to be protected and conserved.  Orchids can easily be eliminated by weeds which choke them.  Consequently, if orchids are found, it is an indication that the surrounding bush is good quality.  It is also important not to pick orchids.  Not only is it illegal, but orchids need their flowers to reproduce.

This is from a leaflet about the common orchids in the Mount Lofty Botanic Gardens.  For the printable version, see here.

Returning… (Part 3)

For today I will be finishing the series of posts I’ve done on this small roadside site, that I visited back in September.

For other parts see: Previous visit, Part 1, Part 2

I was hoping to see some Thelymitra, sun orchids in flower, but they were not ready even though the day was warm.

There were some Pterostylis nutans, nodding green-hoods flowering.  They really do nod in the wind!

There were some other green-hoods up, one being Pterostylis pedunculata, the maroon green-hood and another being Linguella nana.

What was most satisfactory was seeing some of the Linguella nana had formed capsules.  That means there will be more plants there in coming years.

Returning… (Part 2)

It is quite exciting to see that now OrchidNotes has 50 subscribers, and it is just over five months such we started this site up!  I always look forward to comments and feedback on our site, so keep them coming. 🙂  And for those who are interested in being showed some orchids, there is a free walk on the 27th October, see here for details.

For this post I will be continuing with some of the discoveries found at this roadside site, and see here for Part 1 and Previous visit.

The Arachnorchis tentaculata or King Spider Orchids were just beginning to open, but most were still in bud.  In June there were just leaves:

But in September, I saw two flowers open:


Waiting to open


Hiding in the wattle leaves

The video shows how the wind can play havoc with photography, but it seemed to work with the video.  The spider orchids now are flowering plenteously and a field of them can be quite spectacular to come across, but difficult to see in a photograph!

Part 3 will be coming soon!

Striking colour

Diuris orientis – Wallflower Orchids or Bulldog

This is a very common donkey orchid, which is always a pleasure to find on a plesant spring day.

These orchids have very vivid colours making them easier to identify

It would have to be one of the most striking, , spring flowering orchids.  In a field of flowers they are quite spectacular, and will often be found with other spring flowering orchids including Diuris pardina (which it commonly hybridizes with), Glossodia major, and Thelymitra sp.  It flowers from September to November, and is found from Western Australia, right across the southern region of Australia to Victoria and Tasmania.

A healthy colony of plants

This orchid has been observed to grow in a variety of habitats and soil types.  It will regularly form colonies which can be very spectacular.

A yellow variety

There is a yellow variety of this orchid.  In South Australia this variation is not particularly common.  Contrastingly in the eastern states, they mainly have the yellow variety and less of the colourful variety that we have here.  Personally I like the colourful one better.  There is reasonable variety between the flowers with some have a deep maroon to vivid purple  and sometimes white on the labellum.

Know Them