Terrestrial orchids – Page 7

Orchids, Insects and Fire

Recently, 10^th February 2016, Anita Marquart, PhD student, Adelaide University spoke at the Field Naturalists Society of South Australia. She is a recipient of the Society’s Lirabenda Endowment Fund Research Grant. At the meeting she gave a summary of her research – Orchids, Insects and Fire: Investigating the impacts of prescribe burning on orchid pollinators in Southern Australia. Though she has not finished collating the data she has kindly supplied a summary of her talk with her preliminary findings.

It is always encouraging to see research on our native orchids. They are the Barometer of the Bush, so the more we can discover about them, hopefully the more we will better understand how to manage our native bushland.

Orchids, Insects and Fire: Investigating the impacts of prescribed burning on orchid pollinators in Southern Australia

Anita Marquart, Renate Faast, José M. Facelli, Andrew Austin

School of Earth and Environmental Sciences,

The University of Adelaide, Adelaide 5005 Australia

PhD Project

Summary

Fire is an important ecological factor in Australian ecosystems. Orchids that depend on specific pollinators may be more susceptible to disturbance than more generalist species. Therefore, declines or changes in pollinator communities due to prescribed burns and wild fires could lead to reduced pollination success and consequently declines in orchid populations. The project combines traditional plant and insect ecology with advanced molecular techniques to identify orchid pollinators and assess their response to prescribed burns and wild fires. Insect relevant habitat characteristics (such as floral abundance, vegetation height, presence of logs, litter and standing litter) were assessed and trapping surveys of potential orchid pollinators were conducted in spring, before and after prescribed burns. The effect of both spring burns and autumn burns is being investigated.

Study sites are located in the Adelaide hills with always one burn and one adjacent control site respectively in Kersbrook Native Forest, Millbrook Reservoir, Para Wirra Recreation Park and South Para Reservoir. Some parts of the study sites in Kersbrook and Millbrook were affected by the Sampson Flat Bushfire. Affected sites are used to compare the effects on orchid pollinators after prescribed burns in contrast to wild fires.

Potential orchid pollinators are being identified using DNA barcoding with the mitochondrial cytochrome oxidase I (COI) gene. Sequencing results will be compared with existing databanks and confirmed using morphological identification. As the data accumulates it will build up a reference library of COI barcodes for the species found in the surveys.

The outcome of this research project might help to advise the optimal management of orchid species under fire-managed regimes in the Mount Lofty region of South Australia, as well as more generally in south eastern Australia.

160219 Anita Marquart Melangyna collatus on Caladenia rigida — A hoverfly, Melangyna collatus on Arachnorchis rigida syn Caldenia rigida (Rigid White Spider Orchid)

Orchids and their pollinators

Native bees, thyninne wasps and Syrphid flies are known orchid pollinators of South Australian orchid species. Orchids of main interest for this study were Caladenia rigida, Caladenia behrii, Caladenia tentaculata and Glossodia major. Caladenia tentaculata and C. behrii are sexually deceptive orchids and are known to be pollinated by thynnine wasps (Bates 2011). In contrast, C. rigida is food advertising and uses a broad range of bee and fly species, such as native bees and hoverflies (Faast et al. 2009). Glossodia major is a generalist in its pollination strategy and is using small native bees of several genera (Bates 2011, personal observations).

Preliminary findings

Syrphid flies were successfully separated into different species using DNA barcoding methods. Results show that we have two dominating species on our field sites in the Adelaide hills. Both species, Melangyna collatus and Symosyrphus grandicornis are common native Australian species. Both species were caught with orchid pollinia attached and were observed on Caladenia rigida flowers.

First findings suggest that hoverflies don’t seem to be much affected by prescribed burns or bushfires. Syrphid fly numbers vary greatly between the years of sampling, but we did not find a significant impact of prescribed burning or the Samson Flat bushfire.

Statistical analyses for the data on syrphids, native bees and thynnine wasps are currently underway.

Preliminary findings suggest that a range of pollinators are still present on field sites after prescribed burns and even after bushfires. Nevertheless, some specific species might be more sensitive to fires and might have disappeared from the study sites. For example, orchids relying on one species of wasp could be more affected by changes in the abundance of their pollinator after fire, than orchids that are pollinated by a number of different insects.

We will have to analyse our results in more detail to look into the specific species composition for the insect families, especially for native bees and thynnines, rather than looking at overall abundance.

160219 Anita Marquart Melangyna collatus with pollinia — Hoverfly, Melangyna collatus with orchid pollinia attached

References:

Faast R, Farrington L, Facelli JM, Austin AD (2009). Bees and white spiders: unravelling the pollination syndrome of Caladenia rigida (Orchidaceae). Australian Journal of Botany 57, 315–325.

Bates, R. J. (2011). South Australia’s Native Orchids. Native Orchid Society of South Australia.

Do Any Orchids Grow Near The Sea?

Orchids are found in a wide range of habitats. One such habitat is the littoral zone or more simply the seaside. The following information is taken from the NOSSA’s CD/DVD South Australia’s Native Orchids 2011.

The Littoral Zone

Many orchid species have a linear distribution following the coastline. Here on the leeward side of sandhills the air is usually moist and mild, few frosts occur so close to the sea and sea-fogs in winter will cause water to drip into the sand which easily soaks up both the moisture and the extra nutrients provided by sea-spray. Some of the best known coastal orchids include the gnats Cyrtostylis robusta, pink fairies Caladenia latifolia, coast onion-orchids, Microtis arenaria and coastal helmet orchids Corysanthes expansa as well as C. despectans. All of these are colony forming species, mostly because the windblown sand would soon cover ‘single plant’ species which start to appear after the second line of dunes.

Coastal species can be a few kilometres from the sea but there are several that grow either at the high tide mark, within sight or sound of the sea or in coastal dunes. Apart from the ones already mentioned above, the following are some others that can potentially be found within sight and sound of the sea.

Acianthus pusillus (Mosquito Orchid)
Arachnorchis cardiochila (Thick Lipped Spider Orchid)
Arachnorchis fragrantissima (Scented Spider Orchid)
Arachnorchis fuliginosa (Coastal Spider Orchid)
Arachnorchis sp Brown Bayonets (Port Lincoln Spider Orchid)
Bunochilus flavovirens (Coastal Banded Greenhood)
Bunochilus littoralis (Lake Saint Clair Banded Greenhood)
Caladenia sp Selfing Coastal Dunes (Little Dune Fingers)
Corunastylis nigricans (Port Lincoln Midge Orchid)
Diuris orientis (Wallflower Orchid or Bulldogs)
Diuris orientis (Wallflower Orchid)
Diplodium erythroconchum (Red shell Orchid)
Glossodia major (Waxlip or Purple Cockatoo Orchid)
Leptoceras menziesii (Hare Orchid, Rabbit Ears)
Leptoceras menziesii (Rabbit Ears Orchid) after a fire
Prasophyllum elatum (Tall Leek Orchid)
Prasophyllum litorale (Vivid Leek Orchid)
Prasophyllum sp Late Coastal Dunes
Pterostylis cucullata (Leafy Greenhood)
Pterostylis curta (Blunt Greenhood)
Thelymitra antennifera (Rabbit Ears; Lemon Sun Orchid)

Unfortunately, where there has been settlement, it is now unusual to find these species so close to the sea.

Discovering Ducks (Orchids that is)!

Each year the Australian Orchid Foundation has an orchid essay competition. The topic for 2014 Essay Competition was Our Favourite Orchid. The orchid featured, unsuprisingly, was the Flying Duck Orchid, Caleana major. The authors were K Yin and Sau-wan Chan. It is an interesting story and well worth the read of their discovering the delights of this unique Australian orchid.

It all started with the arrival of an email from Sau-wan’s sister who lives in Hong Kong with an article about the Flying Duck Orchid. The article contained lovely pictures of this orchid taken from different angles. It stated that this orchid from Down Under was as unique to the Australian flora as the kangaroo and platypus were to the Australian fauna. The orchid even had a stamp from Australian Post released in its honour! The email ended with the question asking us if we had seen the orchid. This really presented a serious challenge to us and we were both embarrassed and curious by this – embarrassed because of the fact that we had neither seen nor even heard of this orchid after having lived in Australia for nearly 40 years. We love the Australian bush and regard ourselves as having at least above average knowledge of Australian flora and fauna amongst our friends. … Read More

caleana major

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Gleanings from the Journals #2 – Harold Goldsack (27/6/1908 – 25/4/1989)

[Primary source material is the NOSSA Journals. Direct quotes from the Journal in blue and additional information in black.]

Sometimes gleanings take much time and effort to locate but other times there is an abundance of information just waiting to be picked up. This was the case when searching the Journal for information on Harold Goldsack.

Upon the death of Dr R S Rogers, Harold Goldsack became the leading authority of South Australian orchids. To quote Peter Hornsby (1977), NOSSA’s first editor, “Harold is undoubtedly the most experienced of our native orchid botanists and knows more of the history of our orchids than anyone alive.”

Though not a foundational member, Harold was one of NOSSA’s early members, joining at the end of 1977. He was both a grower of epiphytes – winning the Champion epiphyte for 1982 (Dendrobium x gracillimum) and terrestrials – producing the first greenhood hybrid, Pterostylis Cutie (baptistii x cucullata) which was registered on 5^th March, 1982. At the meetings he gave talks, plant commentaries and judged the orchids. Outside of the meetings he was active in advancing the cause of Australian orchids. His enthusiasm influenced many people, one person being a young Mark Clements, current Research Scientist, Centre for Australian National Biodiversity Research, CSIRO, Canberra.

It is not surprising than that in 1984 he was made NOSSA’s second life member.

Bob Bates wrote an informative biography in Harold’s obituary.

Journal 1989 Volume 13 N^o 4 May

Vale Harold Goldsack.

It is with sadness that we announce the passing of life member Harold Goldsack on April 25th. Our sympathies to his family.

Harold was born in East Bengal, India on 27th June 1908. He once told how he could remember epiphytic orchids blooming outside the bedroom window of his childhood home.

His family moved to Adelaide in 1916 and he attended Princes College as a boarding student.

He was introduced to South Australian orchids in bushland adjacent his family’s orchard at Coromandel Valley using Rogers “Introduction to the Study of South Australian Orchids” to identify these. Harold in 1924 introduced himself to Dr Rogers and they became good friends. Harold soon began to find orchids that were new to Dr Rogers and this fired his enthusiasm so that he began a serious study of our orchid flora.

One day in 1928 on a visit to Dr Rogers, Harold was shown the very first collection of the underground orchid Rhizanthella gardeneri. This was to be the subject of the last article Harold wrote over 50 years later.

With the passing of Dr Rogers in 1942 Harold became the foremost authority on South Australian orchids corresponding regularly with H M R Rupp, W H Nicholls and A W Dockrill. His extensive collection of pressed orchids was donated to the State Herbarium in 1978.

Harold wrote many articles on orchids his best known being “Common Orchids of South Australia” which appeared in the S Aust Naturalist in June 1944 and was used in “National Parks and Wild Life Reserves” book from 1965-1970. Harold also revised the orchid section of Black’s “Flora S Australia” in 1943.

Besides drawing and photographing the S Aust orchids Harold developed a large personal Orchid Library and cultivated many Australian orchids which he displayed at shows including our NOSSA shows. The first registered Pterostylis hybrid Ptst. Cutie was made by Harold and the name given to the original clone now grown by hundreds of orchid lovers is “Harolds Pride!”

His main interest was to enthuse others to see the beauty and value of our native orchids through his articles and the many illustrated talks he gave to natural history groups.

Harold was a member of the Royal Society of S Australia.

He was a Foundation Member of the Australian Native Orchid Society. (ANOS)

Ever ready for a challenge Harold at age 64 began studying for his Engineering and Surveying Certificate gaining distinctions in Maths, then working on the surveying of the S E Freeway.

Harold Goldsack’s name is commemorated in the South Australian endemic orchid Prasophyllum goldsackii, a fitting tribute to a true orchid lover.

R Bates

53KB Prasaphyllum goldsackii — Prasophyllum goldsackii – Photographer Ken Bayley

Bibliography of Papers by Harold Goldsack

Orchids of Coromandel Valley – SA Naturalist XIV, Nov 1932 PP 12 – 15

Notes on Caladenia Catifolia – R Br SA Naturalist XV, March 1934, pp 59 – 63

National Park of South Australia – Field Naturalists Sect. of Royal Soc of SA 1936, Being Vol XVII, Nos 1 to 4 of SA Naturalist pp 52 – 54 Orchids

Common Orchids of South Australia – SA Naturalist XXII June 1944 PP 1 – 12 with line drawings of 52 species

New Orchid Records for South Australia – SA Naturalist XXII June 1944, p 13

National Park and Reserves – Commissioners of the National Park, Sept 1956 pp 59 – 79 with line drawings of 52 species of Orchids, p 195 Distribution and flowering times of orchids in the National Park and Reserves

SA National Parks and Wild Life Reserves – Commissioners of the National Park and Wild Life Reserves, March 1964, pp 46 – 64 Orchids with line drawings of 52 species, pp 189 – 199. Distribution and Flowering times of Orchids in the National Park and Reserves

Orchids of the National Park and Wild Life Reserves – Reprinted 1965 by Field Naturalists Society, if (sic) SA from “SA National Parks and Wild Life Reserves” with permission of the Commissioners of the National Park and Wild Life Reserves

Blacks’ Flora of South Australia – Revised edition of p1, 1946 Assisted Rev H M R Rupp and W H Nicholls with the revision of the Orchidacea

Pollination of Caladenia deformis R Br – R S Rogers transactions of Royal Society of SA Volume LV Oct 1931 The pollination of Caladenia deformis as observed by H G was written up by Dr R S Rogers in an article for the Royal Society of SA

Rhizanthella gardnerii R S Rogers – The Orchadian p 113 Sept 1979 A note about the discovery of this orchid

Following is the article by Harold Goldsack referred to by Bob Bates in Harold’s obituary. Though he wrote for other publications, this was appears to be the only one in the NOSSA Journals.

Journal 1979 Volume 3 N^o 8 August

RHIZANTHELLA GARDNERI Rogers Harold Goldsack

Corrigin, Shackleton, Goomalling, Munglingup. Western Australia.

A new locality where the subterranean orchid Rhizanthelle gardneri Rogers has been found, as noted by Don Voigt in his letter to Roy Hargreaves to brings with it hope that after 50 years the secret life of the remarkable orchid may be unveiled. It also brings back memories of my first encounter with this plant.

As a young orchid enthusiast I had been collecting for, and writing to, Dr R.S. Rogers of Adelaide, who, at that time, was an extremely busy public personality. To my surprise, one day in 1928 I received a note from Dr Rogers inviting me to call at his house in Hutt Street after surgery hours as he had something to show me which he was sure would be of interest.

Naturally, I took the first opportunity to visit the Doctor, whereon he brought into the room a large jar with some white vegetable pickled in it. With a smile he said “Have you ever seen anything like this before?”

Well, there it was – this unique subterranean orchid from Corrigin, Western Australia, sent over by Mr C A Gardiner, the Government Botanist of Perth, who had realised the importance of this discovery.

The first plants were found in an area of virgin lane that had been rolled, burnt and then ploughed, which operation uncovered the white underground rhizomes. Mr John Trott, the discoverer, was puzzled by this strange plant growing around the stumps of Melaleuca uncinata R Br, common in the area, and sent it to Mr C A Gardiner. He, realizing the orchidaceous nature of the plant, visited the area, made personal observations and then sent a specimen to Dr Rogers for study, which led to the description of a now sub-tribe, genus and species of orchid – Rhizanthella gardneri Rogers.

Soon after this the Field Naturalists Society were to hold their Wild Flower Show in the Adelaide Town hall and attempted to have this unique specimen displayed there. However, the plant was too valuable to risk and an artist – Mr Lyall Lush – made a black and white drawings which was exhibited instead.

Within three years, on the east coast of Australia at Bulahdelah, another subterranean orchid Cryptanthemis slateri Rupp was unearthed. Unearthed is the word, for this one was unearthed by Mr Slater who was digging up rhizomes of Dipodium punctatum, the “Wild Hyacinth”, to attempt to grow them. All plants of the new orchid were found growing in association Dipodium. The importance of this find was such that Rev H I R Rupp was given a grant to travel to Bulahdelah to make further studies. This second find aroused worldwide interest and a German botanist suggested that the flowers of Cryptanthemis slateri were underground spikes of Dipodium. The morphology of the flowers soon disproved that theory.

Regarding this orchid, which Rupp named in 1932, Dr Rogers commented to me that he was sure that Rev Rupp’s parishioners must have had a very brief sermon the week Rupp received the first specimen of Cryptanthemis!

Dr Rogers then lamented that the orchid hunter has to add a plough and a pick to his orchid collecting equipment!!

November 2015 Winning Photograph

November’s theme was hybrids. Orchids, more than any other plant family, are likely to produce natural hybrids. Even though the overall occurrence of natural hybridisation in orchids is low, it occurs often enough to make some species identification challenging.

Hybrids mainly occur between species of the same genera such as Jenny Pauley’s Arachnorchis brumalis x A. conferta

11sm JP Arachnorchis brumalis x conferta — *Arachnorchis brumalis* x *A. conferta*

but, less commonly, it can occur between genera as seen with Pauline Meyer’s Caladenia latifolia x A. brumalis

11 sm PM C latifolia X A brumalis — *Caladenia latifolia* x *Arachnorchis brumalis*

and her Western Australian photograph of Caladenia x enigma; a hybrid between C. falcata and Drakonorchis barbarossa.

11sm PM Caladenia x enigma — Caladenia x enigma

Jones (2006) states that “Natural hybrids are more common in some genera, such as Arachnorchis, Caladenia and Diuris, than in others.” To this list could be added Thelymitra as seen with both of the winning pictures T. x truncata and T. x irregularis. Interestingly with these two hybrids, the parents are not always the same; the parents for T. irregularis could be T. ixiodies or T. juncifolia with either T. carnea or T. rubra.

11 sm RAL Thelymitra x irregularis.jpg — *Thelymitra*
x *irregularis*

A similar situation occurs with T. truncata with the parents consisting of T. juncifolia and any member of the T. pauciflora (including T. albiflora, T. arenaria, T. bracteata, T. brevifolia, T. cyanapicata, T. pauciflora) or of the T. nuda complex.

11 sm RWL Thelymitra x truncata — *Thelymitra*
x *truncata*

The conditions necessary for hybridisation are that the parents must grow in the same area, have overlapping flowering time and share the pollinator. Brown et al (2103) make the additional observation – Hybrids are more common between wasp and bee-pollinated species than between two wasp-pollinated species or two bee-pollinated species. … However, rare hybrids between species using the same pollination strategies, do occasionally occur …

Obviously hybridisation is more likely to occur when there is an abundance of the parent species. This situation can occur when there is mass flowering following fires or good seasonal rains. Site disturbances either through natural causes or clearing can result in increased incidence of hybridisation.

Hybrids are often infertile and will only last for the life of the individual plant but some have the ability to reproduce vegetatively and, provided the conditions remain favourable, may persist for several years.

One situation that can occur is hybrid swarm. When these occur they can make orchid identification challenging. Hybrids share the characteristic of both parents and by careful observation this can be deduced but swarms introduce an added complexity because the hybrid can backcross with either of the parents or cross fertilise with themselves. The result is a wide range of variation which makes orchid identification difficult.

Finally, some orchids will not hybridise even though the conditions are right. This could be due to specific pollinator or possibly chemical or genetic barriers.

References:

Brown et al (2013) Field Guide to the Orchids of Western Australia, Floreat, WA, Simon Nevill Publications

Jeans, Jeffrey & Backhouse, Gary (2006) Wild Orchids of Victoria, Seaford Vic, Aquatic Photographics

Jones, David (1988) Native Orchids of Australia, Frenchs Forest, NSW, Reed Books

Jones, David (2006) A Complete Guide to Native Orchids of Australia including the Islands and Territories, Frenchs Forest, NSW, Reed New Holland

Introduction to Australian Orchidaceae CD-ROM

https://www.anbg.gov.au/cpbr/cd-keys/orchidkey/html/intro-c_hybrid.html accessed 7^th December 2015

Bates, Robert (2011) South Australia’s Native Orchids NOSSA DVD Adelaide

Spotted Pink Sun Orchid – Beautiful, but Only a Hybrid

https://nossa.org.au/2014/09/26/thelymitra-x-irregularis-beautiful-but-only-a-hybrid/ accessed 7^th December 2015

Does South Australia Have a Christmas Orchid?

Western Australia has the Christmas Spider Orchid (Caladenia serotina) and the Christmas Leek Orchid (Prasophyllum brownie) whilst in the rainforest of the eastern seaboard is the Christmas Orchid (Calanthe triplicata).

In the disc South Australia’s Native Orchids, 2011, no orchid has the common name of Christmas Orchid but there are several listed that could be a possible candidate. The ones that springs to mind are from the genus Dipodium. In South Australia, there are four species flowering at this time:

D. campanulatum (Bell Hyacinth Orchid)
D. punctatum (Dark Spotted Hyacinth Orchid),
D. roseum (Common Hyacinth Orchid)
Dipodium roseum
D. pardalinum (Small Spotted Hyacinth Orchid)
Dipodium pardalinum – Note the yellow staining on the bud and no stripes on the labellum

All four are in flower now – D. campanulatum and D. punctatum in the South East and D. roseum and D. pardalinum in the Southern Lofty Ranges.

There have been other orchids which would have flowered over the Christmas period but in recent days we are have been having an increasing number of dry year, especially this year (2015) which has resulted in the orchids flowering earlier. For example, Prasophyllum murfetii

Prasophyllum murfettii sm — Prasophyllum murfettii (Denzel’s Leek Orchid)

finished flowering in November instead of December and Thelymitra circumsepta

finished flowering in early December but has been seen in flower soon after Christmas Day.

So does South Australia have a Christmas Orchid? Until 1991, D. roseum was included under D. punctatum and the common name according to Bates and Weber 1990 was Christmas Orchid. It seems a pity that when the split was made that neither species retained the common name but nevertheless as they both flower at Christmas, we do have a Christmas Orchid or two!

Reference:

Bates R J, Ed, 2011 South Australia’s Native Orchids, NOSSA

Bates R J & Weber J Z, 1990 Orchids of South Australia

A Timely Reminder

This article is reprinted from Volume 39 No 11 December 2015 Native Orchid Society of South Australia Inc. Journal

Tuber Repotting Time is here

Les Nesbitt

Now that Australian terrestrial orchids have gone into dormancy it is time to think about repotting and preparing for the next growing season.

The best months for this activity are December and January.

I will limit this discussion to the easily grown colony forming terrestrial orchids as these are more likely to be available – for easily grown terrestrials, click here.

IMPORTANCE AND NECESSITY OF GROWING SOUTH AUSTRALIAN ORCHIDS

We need more terrestrial growers in NOSSA to feed the tuber bank and to supply spare pots for sale to the public at the Spring Show. I found it embarrassing to see so few terrestrials for sale at the 2015 Spring Show compared to the numbers available in years gone by.

Growing terrestrials is a rewarding hobby that does not take up much time or space and will pay for itself. Plus you are doing something effective orchids and the environment even if only the most common terrestrials are grown (eg the greenhoods and onion orchids). Consider easily grown, fast multiplying, Pterostylis curta (listed as rare in the SA Act) has been widely grown in NOSSA collections since the days Roy Hargreave’s wash trough when NOSSA was formed.

Once the basic principles are understood it to move onto the rarer species as artificially propagated plants become available in future as they surely will. Members can draw on the tuber bank in December to get started seriously about it as a group of volunteers will be needed within a year or two to help look after the output of a number of projects already underway or about to start.

Year 8 girls at Kildare College have been repotting the school’s terrestrial collection and this is how they did it.

EQUIPMENT

Prepare all the materials needed including:

Pots
crocking material,
sand
organic matter
- blood & bone, native compost, chopped up sheoak needles
4B pencil and labels.

PREPARATION

Water the pots lightly a day or two before repotting. The mix should be damp enough to not be dusty, yet dry enough to not stick to everything.
Remove the label, wash it in a container of water and stand it aside to dry.
Check on the label back to see how many tubers were planted last year.

REPOTTING

Scrape off and dump the top layer of soil as this can be contaminated with moss, slimy bacteria and liverworts.

Tap out the plug of soil into a sieve sitting on a bowl. Pick out any tubers that are visible on the outside of the plug.
Gently break the soil apart and search for tubers while squashing the lumps of mix through the sieve.
- Very small tubers may go through especially with Corybas. If you have not got a sieve do this operation on a sheet of newspaper.

Place the tubers in a dish so they do not roll away.

Count the new tubers to see whether they increased by 2, 3 or 4 times.
Discard anything left in the sieve (old tubers, roots etc.).
Work out how many new pots are needed to plant all the new tubers.

Add to the old mix in the bowl

a pinch of blood & bone,
a handful of sand and a handful of native potting mix.
- Also add enough of these ingredients for each additional pot and mix the contents of the bowl together.

Select new or sterilised 125 mm standard pots

and place a square of shadecloth in the bottom to keep the sand in and critters out.
Pour in mix to within 30 mm of the top and ram down with your fist.
Place up to 10 tubers on top of the mix.
- Lay tubers horizontally if unsure which is the top.

Labelling and finishing the task

Write out the orchid name on extra labels and fill in the numbers of tubers on the back for each pot.
Almost fill the pot with mix and tamp down.
Insert the label. Place a layer of cut sheoak needles on top of the mix.
Water the pots and the job is done.

For show pots use 175 mm or larger pots and plant 20 to 50 of the largest tubers available.

If the tubers have decreased or look unhealthy, throw out all the old mix and replant in new mix.

Growing Terrestrial Orchids Part One of Four

Growing Terrestrial Orchids Part Two of Four

Growing Terrestrial Orchids Part Three of Four

Protect Our Orchids – Stay on the Path

This week there was a workshop South Lofty Block Orchid Recovery Project with representatives from Adelaide and Mt Lofty Ranges Natural Resource Management, SA Water, Forestry SA, Park Rangers, Threatened Plant Action Group and NOSSA. Many issues were discussed. One issue briefly discussed was the development of unofficial bike and walking tracks in parks and the negative impact that this would have on rare and endangered orchids.

This issue is not unique to Australia, the American Orchid Society whose mantra is Education, Conservation and Research published in their journal Orchid February 2008 a summary article titled Watch Your Step: Possible Consequences of Walking off the Trail. The authors are Maryilyn H.S. Light and Michael Mcconaill and the original paper can be found in the Lankesteriana 7:294 – 298 Click on the titles to read the articles.

The researchers studied the effects of visiting a site once a day and standing in the same spot for 10 minutes ie the effects of trampling. Their research suggested that there are possible longer term consequences as they found that the effects of compaction was still observable 18 months later. This does not seem like much but it was sufficient for them to offer some advice such as

stay on the tracks,
don’t walk on the side as even walking on the side of the track can result in unintended damage as the track is widened,
when one person walks off the track others are likely to follow
think carefully of the consequences before walking off the track
where possible step on rocks, not soil

The research was carried out in Canada and though there are differences between the two countries, there are so many similarities it is worth our while to take note of their advice.

Possibly there is scope for research here in South Australia but in the meantime their summary sentence says it all – Until we know what is happening beneath our feet, we should really watch our step

Stay on the Path — Fortunately our orchids like the edges of paths and so the are easy to spot. But at the same time, trampling on the edge of the paths means that the orchids can be destroyed and so be lost forever.

Related Article

Orchid Etiquette – Tread Carefully

From the Journals: A Tale of Two Cities – London & Burnside

The following article written by Robert and Rosalie Lawrence is from the Volume 37 No 9 October 2013 Journal of the Native Orchid Society of South Australia

Orchids and the concrete jungle that makes up a city don’t seem together, particularly the terrestrial orchids. Yet in the heart of one of the world’s most well known capital cities such an orchid was found. On the 19^th July 2013, the Telegraph reported that botanists from the Natural History Museum had found in the middle of London a white helleborine orchid (Cephalanthera damasonium) which had not been seen in that region since 1900. It was found in the Queen’s backyard, Buckingham Palace. Despite the building, demolishing, rebuilding, bombing and rebuilding that has been going on for the last 400 years, here is an orchid which has survived to surprise the botanist. (For details see Long Lost orchid found in Buckingham Palace Garden)

It is always heartening to hear good news about orchids but here in Adelaide we have our own encouraging story. Settlement in Adelaide is not as long as in London by a long shot but in our own short time we have managed to clear and cover some very good land with concrete and bitumen. The result has been that much of our native flora has been lost with many of our orchid species being the first to disappear.

In recent years effort has been made to bring back the bush with revegetation projects. This work has not tended to involve the orchids, the work of Heather Whiting and her team of volunteers at Vale Park being an exception. Consequently, any orchids found on such sites tend to be the more robust species principally Pterostylis pedunculata, Microtis sp. and in some cases Linguella sp.

Finding anything else will always be special; but that is what has happened at site where a Shell petrol station stood for decades on the corner of Portrush and Greenhill Roads. After the demolition of the service station the site was an area of bare clay for about a decade. Then in 2003, work began on restoring native vegetation incorporating a mini wetland in an area of 2,000 square metres that was given the name Linden “Bush Garden”. Indigenous flora was sourced from the local region and the site has been kept meticulously weed-free by dedicated workers.

Originally 60 local species were planted with several other species arriving by themselves. Among the latter group are five species of orchids. These include a Microtis species and Pterostylis pedunculata, but the other three are more surprizing – Arachnorchis tentaculata, a small blue-flowered Thelymitra species and a Caladenia (syn Petalochilus) species. How they came to be there is a mystery. The long term viability of them will depend upon the continued maintenance of this unique site.

The City of Burnside should be congratulated both for its foresight and initiative as well as its ongoing support of this project.

Orchid 1 Arachnorchis tentaculata — Natural regeneration at Linden Gardens includes three plants of Arachnorchis tentaculata (King spider Orchid) that are understood to have flowered for the first time this year (2013). The buildings of the council chambers can be seen in the background.

2015 October Winning Photo

Again this month was a varied selection of species with Pauline Myers’ Caladenia chapmanii (WA), Claire Chesson’s Thelymitra rubra, Jenny Pauley’s hybrid of Arachnorchis brumalis x conferta, David Hirst’s Caladenia discoidea and the winning entry, Rosalie Lawrence’s Diuris brevifolia.

This strikingly yellow flowered donkey orchid endemic to South Australia is listed as Endangered. Its range was once quite widespread in the southern Adelaide Mt Lofty Range region but now it is now restricted to pockets on the Fleurieu Peninsula and western Kangaroo Island in Heathy Woodland, Wetland and Riparian habitats.

There is interest today in cultivating orchids for conservation or ex situ conservation. With the reduced range of this species, can it be cultivated and thus continue to ensure its survival as a species? Some sources seem to suggest that it is an easy plant to cultivate, and some Diuris are easier than others, but Les Nesbitt points out that he has some plants from a rescue dig several years ago and that they have not multiplied very much in that time. This suggests that they may be dependent on a specific fungi. Though it has not been hugely successful in cultivation, it is worth noting that it has been used to produce hybrids with several other Diuris.

Reference

Bates, R. J. (2011) South Australia’s Native Orchids NOSSA DVD, Adelaide

Nesbitt, L personal communications

Adelaide and Mount Lofty Ranges South Australia Threatened Species Profile Fact Sheet – Diuris brevifolia

Summary

Orchids and their pollinators

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