Category Archives: September

Lemon scented

Thelymitra antennifera – Rabbit Ears

The genus of sun orchids can be quite daunting to identify, but thankfully in South Australia Thelymitra antennifera is the most commonly encountered yellow sun orchid with its distinctive column.  It has two common names.  Rabbit ears describe the dark red “ears” that sit on top of the column.  The second name is Lemon Scented Sun orchid, which describes the soft scent emitted by these flowers.

Thelymitra antennifera

This sun orchid has thin grass like leaf with a dark purple base.  The plants quite commonly have several flowers on them.  The flowers are relatively large compared to the small, short stem that holds them.

The Rabbit Ears sun orchid can be found right across Australia from Western Australia into Victoria and Tasmania.  It tends to enjoy a slightly opened woodland, and can be often found on the top of ridges and further down in the valleys.  It is common, and has a long flowering range.  Depending on the region, it can be seen in flower from August to November on any warm day.

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The Mayfly

Nemacianthus caudatus – Mayfly Orchid

Acianthus pusillusThis little orchid is very similar to Acianthus pusillus but flowers in spring instead of autumn.  It has similar heart-shaped leaves to Acianthus pusillus, but the flowers are very differentThey are often found growing together.

The Mayfly orchid has graceful long sepals compared to a relatively small flower.  The whole flower stalk is a dark red, which makes it a challenging subject to photograph in low light.

It is often found growing at the base of tress in the leaf litter, in small colonies.  The flowers attracts its pollinator, a small gnat, by giving off a musty odour which we can also detect.  Once pollinated, the ovaries (pictured left) swell with many tiny seeds within.

Nemacianthus caudatus.docx

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A beauty

A couple of posts ago, I mentioned that I wanted to see some Arachnorchis rigidaI was able to do this last week, and they looked as beautiful as ever.

Arachnorchis rigida

Arachnorchis rigida

These orchids are quite small as can be seen in this picture.  There were fourteen plants in flower with two in bud.

Arachnorchis rigida

There were quite a lot of other orchid species that I saw both in bud and in flower.  It was a very good site, and I am looking forward to heading back soon to get some more photographs.  Have a good weekend.

Orchids in the City Part 2

So today I got my hands dirty at the Vale Park open day.  (See here for Part 1)  I had the privilege of planting out some orchids, namely Thelymitra antennifera, also known as the Lemon Scented Orchid or the Rabbit ears sun orchid.  The orchids I planted were very young plants, only just beginning to grow.  They had been propagated from seeds, and grown in a flask.  Some were just tubers, while others did have some leaves just beginning to emerge.  Unfortunately, I forgot to photograph any before planting.  After we had finished planting, this is what they looked like.

Thelymitra antennifera plants

This species has nice yellow flowers, which gives of a soft lemon scent.  They only open when it is warm enough, as this is when the pollinators are about.

Thelymitra antennifera

A nice specimen of Thelymitra antennifera found in the wild

During the last fortnight, many of the Caladenia latifolia had been pollinated and were forming nice capsules.  This means there should be lots of seeds, and will help these orchids spread.

Caladenia latifolia

Some other orchids which had opened during the last fortnight included Diuris behrii and Diuris orientis.

Vale park is not the only place in Adelaide where orchids have been successfully introduced.  On Gilbert Street in North Adelaide there are some more Caladenia latifolia which are thriving.  This is a smaller site, and did not have as many species.

Caladenia latifolia

So I’ll finish today’s post with a picture that I took near these orchids, right in the centre of the city!

Adelaide Australia

An Orchid Survey at Halbury

Today I took part in a survey of an endangered population of Oligochaetochilus lepidus (Halbury Greenhood).  The area had been surveyed three years previously and the first task today was to find and mark the 20 metre grid.  We then went through and marked all of the plants in flower with little coloured flags.  There were two other species.  Oligochaetochilus pusillus (Small Rusty-hood) was smaller and had blunt reddish tips on the sepals.  Oligochaetochilus aff. excelsa (Dryland Greenhood) had much larger rosettes, thicker stems and was only in early bud stage.  Oligochaetochilus lepidus was almost all out in flower and had distinctive thin tips to the sepals.

Oligochaetochilus lepidus

After lunch I found a path of Oligochaetochilus lepidus.  After marking all that I could find I thought I should count them.  There were 45 in an area little more than a metre square.

Oligochaetochilus lepidus

After an initial search, a final search was done in each quadrat.  Then all of the coloured flags were collected and counted and a figure recorded for each quadrat.  I expect the results will show that there were several hundred plants in this 3 hectare area of mallee remnant vegetation.

This was an example of a citizen science project led by a botanist with ten others involved.

While there I took an interest in the other orchids: there was a population of several flowering Arachnorchis tensa (Inland Green-comb Spider-orchid) and a couple of colonies of Diplodium robustum (Large Shell-orchid) with flowers almost all finished.  There was also a scattering of plants of one of the Hymenochilus muticus group; it appears to be Hymenochilus pisinnus (Tiny Shell Orchid).  There were two bright pink Petalochilus carneus (Pink Fingers) that I found late in the day before driving home for an hour and a half.

Orchids in the City Part 1

Normally you would not expect to find orchids growing and thriving in the heart of the city.  The scene below does not very suggest that there is the right habitat for orchids, yet growing on the hill side are about ten to twenty different orchid species.  These orchids have been planted here.

Vale park

This is a small site in Vale Park, next to the Torrens River and just off Ascot Avenue.  It is a public site, with many cyclists and pedestrians passing it on a daily basis.  To cater for the public there are small paths that wander through the planting.

Vale Park Orchids

All the orchids are marked out with small signs which give tell the name of the plant and show the leaf and flower.  This made it very easy to find the orchids.  Surprisingly, not many of the orchids have been dug up.  This is because it is a public place, and the community wants to protect it.

When I visited the site yesterday, there were a few species in flower, and many in leaf or with buds.  There were a lot of Caladenia latifolia (white form – also known as pink fairies) in flower.  I only saw one plant which had the normal pink flowers, all the rest were white.

Another species that I saw was Pterostylis curta.  There were quite a lot of these orchids in flower as well.

Other species seen, included Diuris orientis, Diuris behrii and Diuris pardina, Glossodia major, Leptoceras menziesii which was in bud, Thelymitra pauciflora and Thelymitra antennifera, and Diplodium robustum.

What is unique about this site is that they have focused on restoring the under-story, which includes successfully establishing some native orchids which have been increasing in numbers.  Often it is very difficult to reintroduce orchids. However in this project, there was an existing woodland before planting.  One orchid was successfully pollinated within a week of planting, indicating that the correct pollinating wasp was present.

This project did have a few difficulties to overcome when it started, such workers inadvertently spraying the orchids, but now the weeding is left to the Vale Park Our Patch group.  There is another site at Gilbert Street, in North Adelaide, and I will leave that one for next week.

If you are interested in seeing this site, there will be an open day on the 14th September from 10am to 3pm.  It is on Ascot Avenue on the Vale Park side of the Torrens River.  It will be interesting seeing how this site develops over time.

The little fellow

Pterostylis pedunculata – Maroon-hoods

Pterostylis pedunculata

This is an attractive little greenhood.  It has a distinct maroon top on the flower and its sepal.  I’ve only seen this orchid with a single flower per stem.  It is a reasonably common orchid, growing in most regions of South Australia, as well as in Victoria, Tasmania, New South Wales and the Australian Capital Territory.

Pterostylis pedunculata

It can often be found in open areas of woodlands, and colonizes easily.  It has a relatively long flowering time, first appearing in late July, and sometimes still flowering up until November.  There is a small rosette of leaves at the base of the plant.  The leaves are crinkled on the top, and spaced wider apart than on other Pterostylis species, such as P. nutans or P. curta.

This is one of the easier orchids to grow.  It is quite a hardy little fellow.  Often this orchid can be introduced to sites through mulch.  The picture on the left shows a maroon hood which was found last year (2012) in the heart of the Adelaide city CBD.

Below is a pretty amazing colony growing in someones front lawn.  So for those who really want to grow orchids, this is one of the easier ones to grow.  (But don’t remove them from the wild, as that is illegal.)

An unusual colony growing in a suburban front lawn. Special thanks to Gordon Ninnes for permission to use his picture.

An unusual colony growing in a suburban front lawn.
Special thanks to Gordon Ninnes for permission to use his picture.

Pterostylis pedunculata

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