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Nice and Early

Eriochilus cucullatus – Parson’s Bands

The Parson’s Bands is a small white flower that appears from late March to May and is reasonably common.  The flowers always appear before the leaves, which can then last some time after flowering has finished.  The whole plant can stand up to fifteen cm high, and usually has one flower per stem, and on rarer occasion can have up to three flowers on one stem.  This orchid appears to like growing in small open places, including rocky places and old tracks.

Eriochilus cuculata (1)

Within the Eriochilus cucullatus species in South Australia there are several subspecies with Eriochilus sp Hills woodland being the most commonly found.  In Victoria only E. cucullatus exists, but there are several other species found in Western Australia.

Eriochilus cuculata (19)

This orchid is believed to be pollinated by a small native bee, which the orchid attracts through its flower’s colouring and scent.  The picture above shows some pollinia on the flower’s labellum.

After it flowers, or towards the end of flowering, the leaves of this orchid begin to appear.  They are a dark green-grey colouring, with a textured top.  If leaves are found at a site, it is probably a good idea to check these areas next autumn for any flowers.

Eriochilus cucullatus

Know Them

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Lurking in the background

As of yet the weed orchid Disa bractreata has not featured on this site, even though it is the orchid I’ve seen the most this year. It is a terrestrial orchid from South Africa and colonizes very quickly.

83b Disa bracteata (17)

Many orchid enthusiasts try to dig them up. This is because their flower spikes produce thousands of very fine seeds that propagate very easily, and take over areas in a couple of years if not controlled. Understandably many try to remove them when on walks looking for native orchids.

So if you want to weed this plant, make sure you have the right plant. Remember that it is illegal to collect any part of any native orchid within Australia, so know what you are dealing with first. These plants are very tough, which is not surprising considering they are a desert plant. I’ve been told that a flower spikes will continue to produce seeds after being dug up. To give an example of how tough these plants are, some plants were up rooted one week ago, placed in a plastic bag and are still continuing to grow.

Disa bractreata

Orchids still growing after one week in a bag

If you do want to weed it, remember to remove the whole plant from the site including the tubers. From there it is best to place them is a plastic bag to cook in the sun.

Disa bractreata

I have not concerned myself about removing these plants as I suspect they may do some good, but it is only a personal theory at the moment that has not been tested yet.  There was a fairly weedy and disturbed site I know about. There were a couple of shrubs and mostly a lot of this weed. It was like this for some time, but over the last couple ofyears, there has been a rapid decrease in the number of weeds and all of a sudden there are lots of sun orchids, Thelymitra, growing there. Maybe the weedy orchids prepared the soil so that the native orchids could grow there. It would be interesting if research was conducted in this area. Have you ever had any experience with this orchid? I would love to hear about it.

Thelymitra sp

One of the Thelymitra that has appeared recently

Gold Hunting

Last weekend, I visited some gold mines in the Adelaide Hills.  I was at a recreation park, and many visitors were there with pick and shovel, and a few even had fancy detectors.  Most did not appear to be very successful in finding gold, which is not surprising considering the site has had thousands of visitors over many years since the mines were closed.

Was I successful?

Well I didn’t find any gold, nor looked for any gold, but I did find some gems.  Yes, those wonderful little orchids are up and flowering already, although not many.  I found some Corunastylis sp. also known as the midge orchid.  These plants are so, so tiny, with the whole plant standing under ten centimetres or three inches,  The flowers can’t really be appreciated unless seen under a microscope, or in a picture.  Unfortunately my camera has been struggling a bit with focusing (and they are too small for my phone camera), so sorry for things being slightly blurry.

Corunastylis

Corunastylis

Corunastylis

Corunastylis

At another site I saw some Eriochilus cucullatus, Parson’s band.  Unfortunately they were not flowering at the time.  Again these plants are still very small, and it can make it very hard to find them.  They have a small white flower.

Eriochilus cucullatus

It wasn’t until I reached home that I realized I had photographed three plants at once (there are three in the picture!).  In this species the leaves do not emerge until after the flowers.

Trial Orchid Monitoring at Belair National Park 1993-1997

April 2013 will be 20 years since a trial of orchid monitoring was done at Belair National Park so it seems like a follow up survey this year could be timely.  A five year study was conducted by members of the Native Orchid Society of South Australia (Bickerton et al 1998).  A follow up survey was conducted in 2007, 10 years after the completion of the previous survey (Bridle & Bridle 2009).

Grey Box (Eucalyptus microcarpa) woodland at Belair National Park in the Adelaide Hills.

Grey Box (Eucalyptus microcarpa) woodland at Belair National Park in the Adelaide Hills.

This post is adapted from Bickerton et al (1998) and is compiled with the assistance of Doug Bickerton who currently works in the Department for the Environment, Water and Natural Resources within the South Australian government.  A future post is planned to present the results and conclusions of the study by Bridle & Bridle (2009).

The original survey was focussed on determining the effect on orchids of removing Boneseed (*Chrysanthemoides monilifera), an environmental weed that invades bushland areas.  This post focusses more on what can be learnt about monitoring orchids.

In 1992 Karen Possingham (newly appointed as was Conservation Officer of the Native Orchid Society of South Australia (NOSSA)) and her husband, Professor Hugh Possingham (President of the Nature Conservation Society of South Australia from 1995-1998) encouraged NOSSA members to conduct an orchid survey trial, with the long-term view of developing a consistent survey method.  A secondary purpose was to collect preliminary data in the response of native orchid populations to the removal of Boneseed.  This is one of the few attempts in Australia to collect long-term systematic data on orchids.  While they were interested in seeing the impact of weeding, they were also very interested to see if a volunteer group could consistently collect data over a long period of time.

The group chose an area of bushland in Belair National Park which was overrun by Boneseed.  Over a 12 month period NOSSA removed Boneseed from the area and during the next five years certain NOSSA members returned at regular intervals to monitor the orchid populations.

Diuris orientis (Wallflower Donkey-orchid or Bulldogs) is a common species at Belair National Park.

Diuris orientis (Wallflower Donkey-orchid or Bulldogs) is a common species at Belair National Park.

SITES AND METHODS

The area chosen for the survey is between Kurra Creek and Workanda Creek, in the northern section of Belair National Park.  In April 1993 they chose three locations (Sites A-C), and pegged out a 20 metre transect at each location.  The sites were all within 20 m of a walking track, and about 100 m apart.

Site A was in open low woodland that was weeded before 1993 and free of Boneseed at the time of the survey; a number of orchid species were present.

Site B was also in open low woodland, was previously heavily infested with Boneseed and was weeded in 1993; no flowering orchids were observed prior to weeding.

Site C was slightly elevated and was more wooded; it was weeded in 1994 and few orchids were present prior to weeding.

Each site was monitored regularly between April 1993 and December 1997.  At each visit, an area of 20 m2 immediately adjacent to the transect was monitored.  This was done by placing a 20 metre rope between the two fixed transect pegs; then a square grid measuring 1 m2 was placed at the beginning of the transect, to the left hand side, and the area within the grid was inspected for orchids.  Then the grid was placed on the opposite side of the transect, and one metre further along the rope.  This process was repeated on alternate sides of the rope, and at one metre intervals, to the end of the transect. By following this same process every visit, the group could ensure that exactly the same ground surface was being inspected each time.

A record was made of the number of orchid leaves, buds, flowers, and seed pods present within the grid.  The species of each orchid was also recorded in most cases, although only the genus was recorded if the species could not be identified conclusively (eg. if only a small leaf was present).  The group also made an informal survey of the surrounding area for five metres either side of the rope.  For the purposes of this report, only the data concerning the flowers in the 20 m2 formal survey area has been considered.  Data on leaves is ignored because of the difficulty in identification, or even finding some species, especially when leaves are small.

The total number of orchid flowers found at each site, for each year of the survey.

The total number of orchid flowers found at each site, for each year of the survey.

RESULTS

Total number of flowering orchids per site

At Site A (the previously weeded site) the total number of flowering orchids declined slightly between 1993 and 1995, from 66 to 50, nevertheless, the number had increased to 105 by 1997.

At Site B, no orchids were seen flowering prior to weeding.  A heavy infestation of boneseed was completely removed from this site, and the following year there were 33 flowering orchids. The number continued to increase each year, so that by 1997 the increase was more than five-fold (174 flowers).

The orchids in flower recorded at Site C declined from 8 in 1993 to 4 in 1994, but after weeding was completed, the overall trend was for an almost ten-fold increase in numbers, to 39 in 1997.

Initial perusal of above graph suggests that the flowering rates of the three sites are different.  The data was not tested for a significant difference between sites, because a time series of five points (in this case five years) is too short to expect a statistically significant result.  The survey would need to be run for at least seven years before a trend could be proved.  The results of a linear regression and coefficient of determination at each site are available to anyone interested.

Number of species of orchids per site

The number of orchid species found flowering at Site A declined from 8 in 1993 to 4 in 1995.  However, this trend was reversed in the next two years, and by 1997 there were 10 species flowering at Site A.  At Site B the trend was similar to that of Site A.  At Site C there was no increase in the number of species flowering between 1993 and 1995, however by 1997 twice as many species were recorded.

The number of orchid species found at each site, during each year of the survey.

The number of orchid species found at each site, during each year of the survey.

Genera Found at each site

At Site A there was a notable increase in Thelymitra flower numbers during the survey (see Table below).  Also three new genera (Orthoceras Arachnorchis, and Petalochilus although the last two of these were recorded as Caladenia species in most of the field notes) had been recorded in small numbers by 1997.  However, for all genera except Thelymitra the trend was for either minor or no increase in flowers.

Table 1 – The orchid genera found flowering at Site A, and the number of flowers found each year.

Genus

 1993

 1994

 1995

 1996

 1997

Corunastylis

3

3

1

Diuris

4

5

4

2

10

Glossodia

2

1

Leptoceras

1

Microtis

2

1

8

Orthoceras

1

1

Petalochilus

2

Thelymitra

54

52

43

78

82

In contrast, every genus found at Site B showed an increase in flowers over the five year survey period (see Table 2). Only three genera (Diuris, Microtis, and Thelymitra) were flowering at the site in 1993, but by 1997 another six genera were flowering. By the end of the survey period there were large numbers of Acianthus, Microtis, and Thelymitra at this site.

Table 2 – The orchid genera found flowering at Site B, and the number of flowers found each year. (Note that Arachnorchis and Petalochilus were both recorded as Caladenia sp. in most of the notes, but two flowers of Caladenia tentaculata are clearly indicated on one data sheet)

Genus

 1993

 1994

 1995

 1996

 1997

Arachnorchis

2

Acianthus

6

1

37

Corysanthes

4

Diuris

4

3

5

5

13

Genoplesium

1

1

5

Glossodia

1

Leptoceras

7

Microtis

1

1

34

42

Petalochilus

2

Thelymitra

28

46

44

40

61

Of the four genera found flowering at Site C in 1993 (Diuris, Glossodia, Leptoceras, and Microtis) none had increased appreciably in number by 1997 (see Table 3).  However, four new genera (Caladenia, Corysanthes, Pterostylis, and Thelymitra) had begun flowering here by 1997, and the number of Thelymitra in particular had increased noticeably.

Table 3 –The orchid genera found flowering at Site C, and the number of flowers found each year.

Genus

 1993

 1994

 1995

 1996

 1997

Caladenia

1

Corysanthes

7

Diuris

1

3

2

4

Glossodia

2

1

3

4

Leptoceras

4

1

1

2

Microtis

1

14

3

3

Pterostylis

1

7

Thelymitra

2

6

9

12

The information in Tables 1-3 above is summarised in Table 4 below:

Table 4 – This table shows the sites at which different genera were flowering, and the number of flowers found each year.

GENUS

SITE

1993

1994

1995

1996

1997

Acianthus

A

 

B

6

1

37

 

C

Arachnorchis

A

 

B

2

 

C

1

Petalochilus

A

2

 

B

2

 

C

Corysanthes

A

 

B

4

 

C

7

Diuris

A

4

5

4

2

10

 

B

4

3

5

5

13

 

C

1

3

2

4

Genoplesium

A

3

3

1

 

B

1

1

5

 

C

Glossodia

A

2

1

 

B

1

 

C

2

1

3

4

Leptoceras

A

1

 

B

7

 

C

4

1

1

2

Microtis

A

2

1

8

 

B

1

1

34

42

 

C

1

14

3

3

Orthoceras

A

1

1

 

B

 

C

Pterostylis

A

 

B

 

C

1

7

Thelymitra

A

54

52

43

78

82

 

B

28

46

44

40

61

C

2

6

9

12

DISCUSSION

In this discussion we will explore the value of the survey method used, and the impact of weeding on the orchid populations.

Experimental design

To assess the impact of Boneseed weeding in a more rigorous fashion, we would need to have a much larger number of more carefully chosen sites.  The ideal design would include four or five replicates of each treatment, where the appropriate treatments might be:

  • Previously weeded
  • Weeded at the start of the survey
  • Weeded during the survey
  • Not weeded

In addition to this, an ideal survey would also continue for about 10 years.  If such a survey method were to be used, the logistics of the task would be significant.  However we propose some changes to the method that was used, and these are listed below.

The survey method

If NOSSA were to survey multi-species orchid populations in the future, with a view to looking at the impact of habitat management, then we suggest the following variations in the method:

  1. Attempt to record the total number of individuals, using leaves and flowers at the time the species is flowering. If it is not possible to positively identify leaves for all species, then only record the flowering plants for some species.
  2. Four carefully timed visits per year, at the same time every year, is probably adequate.
  3. The whole 40 m2 should be marked and used to compile a simple species list.

By using this faster method, greater replication could be achieved.

The impact of weeding on the total orchid population

If we look at the total number of orchid flowers found at each site (see Figure 3), it is evident that Sites B and C improved at a much greater rate than Site A (which had been weeded previously).  It is also apparent at first glance that Site B, which was weeded just before observations began, fared better than Site C, which was not completely weeded until 1994.  Admittedly the total Site B population improved by 178 flowers, compared with less than 39 at Site C, but the dominant Eucalypt trees near Site C were larger and they created more shade than at Site B.  Hence the environmental conditions are likely to be a confounding factor in the difference between all sites.

CONCLUSION

Despite the shortcomings of the survey method used, it appears that the removal of Boneseed from open Eucalyptus microcarpa woodland is beneficial to the populations of at least 50% of the orchid species known to occur in such habitats, and is not detrimental to any orchid species.  We urge NOSSA to explore the impact of other habitat management actions, using a revised version of the method described here.

ACKNOWLEDGEMENTS

We wish to thank the National Parks and Wildlife Service for permission to carry out the survey at Belair National Park.  We also thank the volunteers who assisted in the survey, including (in alphabetical order) Roger Bidell, Phil and Thelma Bridle, Gerry Carne, Bill Dear, Cecil and Margaret Hollamby, Malcolm and Cathy Houston, Andrew and Kathryn Lloyd, Greg Miles, Ray Nash, Thelma O’Neil, John and Joan Peace and David Pettifor.  Their enthusiasm, skill, and patience showed that NOSSA is capable of doing repeatable systematic surveys of high quality.

REFERENCES:

Bickerton D, Possingham K & Possingham H (1998). The Effects of Boneseed Weeding on Orchid Populations at Belair National Park (South Australia) and a Trial of an Orchid Survey Method. Report for the Native Orchid Society of South Australia, Adelaide.

Bridle T & Bridle P (2009).  2007 Update on the Effects of Boneseed Weeding on Orchid Populations at Belair National Park 1993-1997.  Journal of the Native Orchid Society of South Australia, Vol. 33 (2): 16-19.

Dormancy of some terrestrial orchids

Philip Roetman, who is also interested in citizen science, directed me to a paper by Nancy Sather summarising 25 years of monitoring of a species of terrestrial orchids in Minnesota, in central North America next to Lake Superior.  I have picked out some points of interest that could be relevant to understanding terrestrial orchids in Australia.

Link for image

The plant monitored was the Platanthera praeclara (Western Prairie Fringed Orchid).  This is a species with up to 24 showy, white flowers on a spike reaching 1.2 metres tall.  It grows in remnant prairies and sedge meadows and sometimes emerges while areas are covered with water.

The paper was published at a conference in August 2012.  It summarises results from 1985-2010.  The number of plants counted peaked at over 10,000 with high counts in the years between 1993 and 1996.  Average counts in 2006 to 2009 were at 15% of those in the high years.

Dormancy is a fascinating feature of these orchids.  In one study, up to 12% of plants were dormant each year and 30% experiencing dormancy of one to three years.  At two sites the average life spans were 4-8 years with individual plants surviving 22-26 years with episodes of dormancy.

I have heard that individual plants of Calochilus cupreus (Copper Beard-orchid) in South Australia do not come up every year.  The remaining population is monitored once every year.

Figure

The Minnesota Department of Natural Resources uses the nested orchid monitoring protocol depicted in Figure 1 (above), with decreasing numbers of sites as intensity of monitoring becomes greater.  These Levels show the possibilities for monitoring for Australian terrestrial orchids.  Those interested in studying orchids will find want to read the detail about these levels and how the data were collected.

A study by Quintana-Ascencio et al. (2004) is cited in which dormancy is reported lasting “as long as eight years, with more than half of all dormancy episodes as short as one year. Rates of dormancy can be quite high. Across the full 25 years of the study at Burnham WMA, 57% of plants that ever flowered and 70% of plants that lived more than three years but never flowered exhibited at least one episode of dormancy.”

Sather (2012) reports that it was possible to observe plants enter and emerge from multiple periods of dormancy.

“Periods of extended dormancy may also help explain the well-recognized tendency for the locus of flowering plants to shift geographically within populations from time to time and the resurgence of orchid populations after near-disappearance or periods of low numbers. Variations in demographic characteristics of populations between sites and years exhibited in preliminary analyses of our data (Quintana-Ascencio et al. 2004) suggest that it is unwise to draw conclusions from short-term studies or to extrapolate between sites. Studies of 3-5 years are insufficient to frame development of recruits to flowering plants and periods of dormancy that last for three or more years.”

Orchid season taking off

It is the beginning of autumn, and that means the orchids will start appearing again.  True there were a few flowering over summer, but about now we begin to see the leaves of the winter flowering species and some spring flowering orchids, and occasionally we might find a few autumn flowering species.

So today, I’m going to give you a sample of some of the orchids you could find, each month, during this coming year.

March

April

May

June

July

August

September

October

November and December

January and February

and then it all starts over again.

For more pictures see here.

Our orchid photographs

I took my first photographs of native orchids in February 2005 at a monthly general meeting of the Native Orchid Society of South Australia (NOSSA).  Orchid growers bring their flowering plants to the monthly meetings to show them and to compete for the best orchids.

2005 Feb 017

This is one of my first photographs of an orchid taken with
a digital camera without a flash in February 2005.  This is a Sarcochilus hybrid.

My aim at the start was quite simple.  I just wanted to get to know the names of the orchids, because I did not know any of them at all.  Three of my photographs from the February meeting turned up in the electronic version of the March NOSSA Journal, including the one above.

In the March 2006 issue of the Journal, because there were few plants at the meeting to photograph, the Editor compiled a page of photographs of orchid leaves which I had taken on a field trip to Scott Conservation Park the previous winter.  Some of these same photographs appear in my book, Start with the Leaves, including the two of the photographs on the front cover.  One couple told me that they took this page with them into the field to identify orchids before they flowered.

Leporella fimbriata 005

This beautiful, newly emerged leaf of Leporella fimbriata is one of my first orchid
photographs taken in the field.  It features prominently on the cover of my book.

My reasons, then, for photographing orchids were so that I could get to know them, and to share them with others.

Incidentally, some of the flowers are strikingly beautiful.  When my children were helping me prepare the book, they were not happy with pictures that just showed the features relevant for identification; they wanted each photograph to be attractive and balanced.

We went on NOSSA field trips to learn about orchids and photographed them to help with this.  We went with our compact cameras while the photographic enthusiasts took their SLR cameras and their tripods.  We found the digital cameras to be adequate for our purposes and all of the pictures on this blog have been taken with either a compact digital camera or a smart phone.

In May 2011 NOSSA began having a photographic competition to give members the opportunity to share their best photographs.  I entered my favourite photograph of Diuris orientis, which I regard as the most photogenic of our orchids because of its size and depth of rich colours.  This photograph was included in the header in an earlier version of the banner for the Trees For Life website.  This was the first photograph to win this competition.

Diuris orientis 026

Diuris orientis photographed in full sunlight on 4 October 2005.
Notice the splendid rich colours.

We have seen a wonderful selection of photographs from members of NOSSA at the general meetings since this first competition.  The only prize is to have the photograph displayed for a month on the NOSSA website.  Unlike most of the followers here who share their photographs on the net, most of the participants have not shown their pictures before.  This event has been about sharing photographs rather than winning prizes.

The people who judged the orchids at the general meeting had set an example of having two of them speak about the orchids that had been “benched.”  So, the practice with the picture competition has been to use this as an opportunity to have somebody speak about the orchids photographed.  There was also an informative Journal article about the monthly winning photograph and a similar post on the NOSSA website.  This educational aspect makes the competition worthwhile.

The pictures displayed at the meetings are only seen by the 30-40 people attending the monthly meetings, but I hope a larger audience will be able to see them.

What bothers me is the thought of hundreds of photographs stored on home computers that have hardly been seen by anyone and are just waiting for a hard drive to crash when they will be lost for ever.  Some may be historical showing orchids where they no longer occur.  I would like to explore this idea on a later post.