Monthly Archives: September 2013

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

Know Them

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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.