Burning Issues

Over the years, we have published several blogs concerning orchids and fire. At the beginning of the year, Renate Faast spoke at the NOSSA February meeting. John Eaton wrote an extensive summary of her talk which is reprodued here as it appeared in the 2019 March edition of the Native Orchid Society of South Australia Journal, Volume 43 Number 2.

Renate’s take home message was that we cannot make sweeping statement about orchids and fire, each species responds differently and we need to take this into account when planning proscribed. This was something that Dr Michael Duncan also brought out in his 2009 report following the Victorian Black Saturday fires – see Orchids and Fire.

An interesting aside to Renate’s research was her observations of white-winged choughs – see the paragraph Not All Relationships are Friendly.

Stipi fire 3Guest Speaker Notes                                John Eaton

At our February 26th meeting, thirty NOSSA members were treated to a stimulating talk by Dr Renate Faast from the University of Adelaide – our first guest speaker for 2019.

Renate acknowledged the support her project received from an Australian Research Council (ARC) grant under the Linkage Program which promotes national and international research partnerships between researchers and publicly funded research agencies – in Renate’s case – support from the University of Adelaide, SA Museum, SA Water, Forestry SA, The Australian Orchid Foundation, the Nature Foundation of SA, The Environment Institute and the SA Government.

Mixed Messages

Renate had been getting mixed messages from the field observations people had made following prescribed burning or bushfires. This ARC grant enabled her to study the impacts of prescribed burning on native terrestrial orchids.

Renate found that the response of orchids to controlled burns suggests that there are winners and losers amongst orchids: Naked sun orchids responded really well to a controlled burn with 6 plants growing to 83 plants. REALLY good news for that species of orchid but the reality is more complicated than that and this study suggests that there are no generalisations that can be drawn with any confidence about regeneration following prescribed burns or bushfires! In view of the complex interactions between orchids and other plants, and between orchids and bird-and-animal grazers, orchids rely on so many things to go right in order to set seed and recruit new plants into a population. With the exception of a few self-pollinating species, most orchids rely on pollinators for seed production. For non-clonal species, releasing seed is the only way to ensure the species’ long-term survival!

Not all relationships are friendly

Over 80% of orchid flowers had been grazed at some sites. No flowers means no seeds. Renate’s film clips embedded in her PowerPoint dramatically showed the extent of orchid predation by birds such as white-winged choughs and currawongs. They picked off the flowers quite deliberately, leaving behind an intact stalk. Five flowers were grazed every 10 sec (that’s at a rate of 30 flowers/min!) And there are all the other orchid grazers such as roos, deer and rabbits as they move through a patch, often only grazing part of the stem, in a far less targeted and thorough way, compared to these birds. All of these interactions play a key role in whether seeds are released to keep the population viable.

The Mount Bold Fire prompt

160219 Anita Marquart Melangyna collatus on Caladenia rigida

While engaged in her PhD research into reproductive ecology of spider orchids, Renate heard that a fire at Mt Bold had led to a “profusion” of Caladenia rigida flowers! The Victorian bushfires had also prompted changes to prescribed burning practises in South Australia. The combination of these two events led Renate to explore the effect of fire on the interactions orchids have with other plants and animals – leading her to ask such questions as:

  • Does fire promote the flowering of spider orchids (e.g. Caladenia rigida, C. behrii, C. tentaculata) and Glossodia major?
  • If there are more flowers following fire, will they be pollinated and will they set seed?
  • How does burn timing influence this response?
  • Do all species respond in the same way?

These are all critical issues to consider if we are to ensure a self-sustaining orchid population in the future.

1710 JH Arachnorchis tentaculata sm

Seasonal Factors

There are seasonal influences on the effects of a burn. The response to a summer bushfire could be quite different from cooler season burns in autumn and spring. And even if some orchids are stimulated to flower, it doesn’t necessarily mean that they will end up producing and releasing more seed – which is what really matters for the long-term survival of the orchid population.

Orchid monitoring was carried out in several sites and included 1 autumn, 3 spring burns and 4 adjacent unburnt control sites across the Mt Lofty Ranges (NE of Adelaide). Renate followed the fate of 4 species by tagging up to 150 plants for each species. Renate’s presentation focused on the Millbrook sites where she studied C. rigida and G. major before and after a prescribed burn conducted in Autumn 2013. Unfortunately and fortuitously, her control site also became a bushfire site following the Sampson Flat Fire in January 2015. Fortunately, the Autumn burn site was not affected by the Sampson Flat Fire, so became something of a control site! Renate found that 97% of C. rigida did not emerge after the Autumn prescribed burn compared with 8% at the unburnt control affected site. Flowering was not promoted and no tagged plants flowered. A similar but less severe effect was recorded for Glossodia major.

Will these orchids recover in subsequent years?

Annual monitoring up until 2017, revealed that over one third of C. rigida plants did not re-emerge for 5 consecutive years after the autumn burn. Unfortunately, these plants are likely to have been killed by this burn, probably because the fire was conducted as the orchids were about to emerge. Interestingly, spring burns did not have a detrimental impact on the orchids studied, however, a proportion (18 – 28%) of C. rigida plants may also have been killed by the summer bushfires.

One of the more striking findings out of this research was the large increase in pollination for C. rigida following the bushfires – up to 65% of flowers (protected from grazing) produced a seed pod – an unprecedented rate for Renate’s research. It seems that in the sparse blackened landscape with very few other plants in flower, C. rigida had most of the attention for pollinators. However, the removal of understorey cover also meant that grazing rates were higher after the fires, and most of the flowers that were not protected inside cages were eaten. This meant that there was no actual benefit to the orchids, as there was no increase in seed release. All of these responses were short-lived, and by spring 2016, pollination, grazing and seed release rates were much the same as before the fires.

Arachnorchis behrii 1
Arachnorchis behrii (Pink Lipped Spider Orchid)

Renate’s Conclusions:

All species are not equal – fires may benefit some species others don’t fare so well;
All fires are not equal;
Autumn burning may be detrimental to SOME species;
Bushfire may benefit seed release, only if grazing pressure is low – and
Flowering was not promoted by any fire.
More research is needed on other species, and in different habitats.

Therefore, Renate pointed out that no generalisations can be made about her observations!

Some good news that has come out of this research:

  • Burn practices are changing, with land managers taking into account the timing of prescribed burns, and bestattempts are made to avoid late autumn burns in areas containing threatened (early-emerging) orchids;
  • Impacts of fire on reproductive success appear to be short-term

Renate’s hope is that one day, the message will get out there that while some orchids can respond well to burning, this isn’t the case for all species – and that we still have a long way to go before we will really understand the complexities that underlie these different responses with any degree of predictability. Renate also warned that over a third of SA’s orchids are threatened with habitat loss, weed invasion, pollinator loss, grazing and fire regimes.

Renate’s address was followed by a flurry of burning questions and observations. It is hoped that we NOSSA members will use Renate’s conclusions to guide and inform our own anecdotal field observations and test our underlying assumptions and prejudices about the effects of burning on orchid viability – especially as we enter an unprecedented and potentially species-destroying period of human – induced global warming.

Stipi fire 2

 

Australian Orchids: The How, Where, When & Why

It’s been a little while in coming, but here is the second of a three part educational video about Australian Orchids.

Orchids are special.

They are unique but even more they are important. Orchids are the barometer to the health of the ecosystem.

So, watch and enjoy the video …

To watch the first video click here.

Good News, They’re Back …

With the lack of rains, it doesn’t look good for the start of the 2019 South Australian orchid season but there is a good news story.

In the February 13, 2019 edition of the Hills Valley Weekly there was an encouraging article of the work of Bush For Life. Part of Trees For Life, this program with the aid of trained volunteers spend numerous hours weeding specific bush sites with the hope that they give our native plants a chance to survive. Yes it requires commitment and dedication but what joy there is when volunteers start seeing plants returning.

Orchids are often the first to disappear from a site when weeds enter and in many instances do not return. For them to return the conditions have to be just right with both the mycorrhizal fungi and the pollinators present. The more orchid species the better the site.

So well done to Jenny McInernay and Trees For Life for their work and commitment.Plants Return to Park

The blue orchid featured in the article is a spring flowering sun orchid; it appears to be Thelymitra inflata, common names Blue Star Sun Orchid or Adelaide Hills Plum Orchid. The other flower is not an orchid. It is a Wurmbea, common name Early Nancy.

Tracking Down the elusive Prasophyllum suttonii

Rudie Kuiter’s Short Paper 2 Taxonomic Status of the Mauve Leek-orchid Prasophyllum suttonii Rogers & Rees, 1912 (Orchidaceae) published in May 2017 documents how he used original source material to determine the identification of a species that was considered extinct.  Prasophyllum suttonii belongs to the Prasophyllum odoratum/diversiflorum complex and is very similar to the later named Prasophyllum alpestre. It was considered to be extinct but Rudie’s view was not that it was extinct but that it had been “lost in taxonomy, and its status need to be restored”. His article documents how he used original material to help determine identification of the species he had photographed.

In his summary Rudie has some good advice about how to effectively use the material available –

  • Use original descriptions and illustrations
    • Original descriptions are preferred over type specimens
    • later descriptions may be based upon second hand information which may or may not be accurate.
  • Drawings have some value but depend
    • upon the skill of the artist to show the crucial details
    • upon whether they were drawings from fresh or preserved specimens
  • A good photograph will be better than a drawing
  • Type material is useful but may deteriorate over time

Images from Rudie Kuiter's article on Prasophyllum suttonii

 

Click here to read the complete article

 

Orchids In Remnant Roadside Vegetation

This week’s post written by Leo Davis is an article (slightly edited) from The South Australian Naturalist 91 (1): 34 – 37 January – June 2017. In this article, Leo highlights the importance of  the role of roadside vegetation in preserving the native orchids and flora.

All photographs are by Leo Davis.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 OrcFig 1: Thelymitra antennifera hybrid

One of my rules of thumb is ‘If I am in a Conservation Park, I’m on ground that nobody could make a living from.’ One, usually more, of nutrient poor soils, excess salinity, extreme rockiness, steepness, poor moisture retention, low rainfall or even being waterlogged, will be a feature of the location. There are a few odd spots that have survived partly intact, that have good soil, sufficient rainfall, etc. These include cemeteries (The Nationally Critically Endangered ghost spider orchid (Caladenia (syn. Arachnorchis) intuta) holds on in a cemetery on Yorke Peninsula) or exclusion zones around water storages (including a reservoir reserve in Lobethal that the public can now access) or abandoned railway yards (including Sherlock, where so far I have found 21 species of orchids and part of a reserve in Halbury.)

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 2: Little Yellow Club Mallee Spider Orchid Caladenia (syn Arachnorchisverrucosa

When I go in search of plants with the Botany Group of the FNSSA (Field Naturalist Society of South Australia), or for orchids with NOSSA (Native Orchid Society of South Australia), or when I do surveys of threatened orchid species with DEWNR (Department Environment, Water and Natural Resources), or orchid seed collection with the Adelaide Botanic Gardens, or go on weeding parties to protect endangered species, the destination is always one of these deprived, rejected sites. The orchids I see are those adapted to or just hanging on in such sites. We never see orchids that lived on better soils, say on the Adelaide Plains. How many have become extinct?

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 3: Common Mallee Shell Orchid Pterostylis dolichochila

Wherever the land was suitable for agriculture it was clear felled. Almost nothing of the original flora and little of its associated fauna, were left. But there is a tiny flimsy exception. Crossing these highly productive agricultural zones are roads and sometimes these have remnant vegetation. For a person interested in orchids, these narrow strips are normally areas of slim pickings but occasionally finds are made. Near Halbury, the Nationally Endangered Halbury rufoushood (Pterostylis sp. Halbury or Oligochaetochilus lepidus) can be found in some roadside spots.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 4: Mallee Bearded Greenhood Pterostylis (syn Plumatichilos) sp. Mallee Bearded Greenhood

The most remarkable piece of roadside vegetation that I have come upon was discovered by and shown to me by Glenn Dean, the Environment Officer with the City of Murray Bridge. He found a section of predominantly broombush (Melaleuca uncinata) vegetation, only about 200 m. long, on the verges of a single car sandy track, east of Murray Bridge. It is so close to the vegetation that cars can be scratched. I have found 24 species of orchid (Glenn has found more) blooming there sometime between March and October each year. All images shown here (Figs 1–11) were made at this site. If the little used road was not there the land would have been under crop, being equal in quality to regularly cropped fields to either side, and is of much higher quality than any normally allocated to Conservation Park status. Most of the orchids found can indeed be found in some of the poor sites dedicated as Conservation Parks, including species similar to those found at Ferries McDonald and Monarto Conservation Parks with their poor sandy soils. But this spot, which for some reason supports species that do not grow just 100 metres east or west along the road, has such species as the Nationally Critically Endangered Mallee Leek Orchid (Prasophyllum constrictum) (Fig. 8), that requires soils as good as those demanded by wheat, so it is essentially doomed.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 5: Rusty Rufoushood Pterostylis biseta (syn Oligochaetochilus bisetus)

Its single plant sighting here is regarded as a ‘rediscovery’ of a species not seen for years. In the longer term I guess this tiny site of orchid species richness is in a transitory state and most species will disappear. The surrounding cropping land is neither a source of seed nor a suitable landing site for it and it provides damaging wind blown nutrients and other chemicals. So I will cherish it while it lasts and hope others appear, if only briefly. Here is a reminder, that most of you do not need, of the value of roadside vegetation (with the understanding that it can contribute to native animal mortality) and that we should manage, extend and guard its presence.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 6: Rufoushood Pterostylis (syn Oligochaetochilus) boormanii complex sp.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 7: Cinnamon Donkey Orchid Diuris palustris

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 8: Mallee Leek Orchid Prasophyllum constrictum

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 9: Limestone Tiny Shell Orchid Pterostylis cycnocephala
(syn Hymenochilus calcicolus)

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 10: Caladenia (syn Jonesiopsis) capillata x Pheladenia deformis hybrid

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 11: Small Rustyhood Pterostylis pusilla (syn Oligochaetochilus pusillus)


Orchids in Medicine?

Question: Are orchids used in medicine?

Answer: Worldwide, some orchids are used medicinally but compared with other families, despite their numerical dominance in the plant world, orchids only contribute a small number of species to medicine.

Orchidaceae is the second** largest Family in the world after Asteraceae which has about 32,280* species whilst the orchids consists of about 27,753 species. In the big picture, their numbers are similar but only 2.32% (619) of all orchids species can be considered medicinal as opposed to 7.17% (2,314) of Asteraceae.

It is worth noting, that only 28,187 (6.48%) of the possible 434,910 species worldwide are recorded as being used medicinally. But of all of the world’s families it is the small Family of Moraceae (Mulberry, Figs & Mallow) that contributes the most. Of its 1,229 species 22.54% are medicinally useful.

 

 Total number species

 

 Percent of species used medicinally

 

 Number of Species used medicinally

 
World wide

434,910

 

6.48%

 

28,187

 
             
Asteraceae

32,280

 

7.17%

 

2,314

 
Orchidaceae

27,753

 

2.23%

 

619

 
Moraceae

1,229

 

22.54%

 

277

Concerning Australian orchids only a handful are known to have been used medicinally such as Cymbidium for dysentery, Dendrobium teretifolium bruised leaves for pain relief and different parts of  Dendrobium discolor as a poultice and for ringworm.

Cym caniculatum drawing

Notes:

**Many sources will state that the Orchid Family is the largest Family worldwide but for the purpose of this article, the information used is from 2017 State of the World’s Plants. Species numbers tend to be a in state of flux as botanists are discovering new and reassessing data.

*All figures in this article are based upon figures found in the 2017 State of the World’s Plants report.

Reference:

https://stateoftheworldsplants.com/ accessed 9 June 2017

https://academic.oup.com/qjmed/article/98/9/625/1547881/The-uses-and-misuses-of-orchids-in-medicine accessed 9 June 2017

 

UPSIDE UPSIDE DOWN

Leo Davis always has some interesting insights from his orchid observations.  In this article he examines the position of the tepals (petals and sepals) in particular the Moose Orchid which he saw for the first time this year.

Have a close look, next season (winter to early summer) at some of our native lilies.  Start with the jolly bulbine lily (Bulbine bulbosa), no longer a true lily incidentally, because it now resides in family Aspodelaceae, along with the grass trees. You will find three yellow petals at 12, 4 and 8 o’clock and closely behind them three almost identical sepals at 2, 6 and 10 o’clock, so at first sight you see six apparently identical tepals (sepals and petals).  Move on to the rush fringe-lily (Thysanotus juncifolius), as described in Ann Prescott’s ‘It’s Blue With Five Petals’.  Clive Chesson is more up to date and tells me it is now T. racemoides.  Again it is no longer a true lily, now sitting in family Asparagaceae.  Here the tepals are noticeably different.  Three wide densely fringe edged petals will be found, if you view the flower face on, at 12, 4 and 8 o’clock.  The narrow non fringed sepals sit close behind at 2, 6 and 10 o’clock.  These are just a generalisations because if the flower turns only about 60o a sepal will be at the top.

Most orchids, while close relatives of the true lilies and the one time lilies, do not show these arrangements.  Let’s start with some that do.

In the large duck orchid (Caleana major) the petal at 12 o’clock, the dorsal petal, is modified, as in most, but as usual, not all, orchids, to become a labellum.  In this charmer the labellum takes the form of a duck’s head.  Its function is to snap down trapping a pollinator insect in the cup shape column below it, forcing it into contact with the sticky off white stigma and/or the yellow pollinia below it.  Look closely and you will find the other two narrow petals drooping at around 4 and 8 o’clock.  Two folded, twisted sepals can be clearly seen at around 1 and 11 o’clock.  The third sepal, at 6 o’clock, is tucked in behind the cup shaped column.  Note that, as with lilies, the top tepal is a petal.

ld-caleana-major
Caleana major, Knott Hill NFR Photographer: Leo Davis

The leek orchids (genus Prasophyllum) follow this pattern and also have their labellum at around 12 o’clock.  These orchid groups, which are up the right way, are said to be ‘not upside down’, using the technical term ‘non resupinate’.

Most orchids are ‘upside down’ and are called resupinate.  The whole flower rotates 180o, clockwise or anti I don’t know, at the embryonic stage.  But let’s start with somewhat of an exception with the sun orchids (genus Thelymitra) which do not have a petal modified as a labellum.  But they are indeed upside down.

Have a close look at the Thelymitra benthamiana flower.  Note that the three petals, at roughly 2, 6 and 10 o’clock, are in front of the three slightly larger but very similar sepals, at 12, 4 and 8 o’clock.

Note that the top tepal is a sepal.  The flower is upside down, that is resupinate.  In most orchids the petal at 6 o’clock would be modified to be a labellum.

ld-thelymitra-benthamiana
Thelymitra benthamiana, Scott Creek CP; Photographer: Leo Davis

The Arachnorchis (possibly Caladenia to you) stricta, from Sherlock, out in the mallee, is more typical of terrestrial orchids in SA.  It is upside down, that is resupinate, and has a petal modified to be a labellum.

The bottom petal has become a wide labellum, with fine edge combs and parallel rows of rich plum coloured calli covering its centre.  Out at roughly 3 o’clock is a narrow petal, the other invisible on the other side.  At the top, pressed tightly against the column, a sepal arches forward.  Two larger sepals extend down at around 5 and 7 o’clock.

ld-arachnorchis-stricta
Arachnorchis stricta, Sherlock; Photographer: Leo Davis

When I saw my first, my only, moose orchid, this season, I was in such a state of excitement that it looked to me to be up the right way, that is to say upside down.

ld-cryptostylis-subulata
Cryptostylis subulata, Stipiturus CP; Photographer: Leo Davis

Have a look.  Two narrow short roughly vertical petals at about 1 and 11 o’clock.  There are two sepals at just past 3 and just before 9 o’clock. That’s OK but where is the other sepal?  Are there it is, where it should be, at midday.  But hang on, it’s behind the flower stem (peduncle) and where is the column?

ld-cryptostylis-subulata-with-labellum
Cyrtostylis subulata with labellum lifted; Photographer: Leo Davis

Holding the labellum up with a stick I found the column, the stigma and the pollinia, underneath the labellum.  The third sepal now appears to be at 6 o’clock.  And it all became clear.  This flower was up the right way (non resupinate) but it has turned forward, on its peduncle, by about 180o, to become upside down, but not in the manner of resupinate flowers, because it is back to front.  It is an inverted non resupinate flower.  Still with me?

Gleanings from the Journal – Have Our Orchids Changed?

Ten years ago, the then NOSSA secretary, Cathy Houston, wrote an article reflecting upon orchid name changes.  Since then there have been more name changes. The issues she raised then are still pertinent today. Whilst we continue to learn more about our orchids, name changes are going to happen.

NOSSA Journal Volume 31 No 2 March 2007

HAVE OUR ORCHIDS CHANGED?                                                           Cathy Houston (Secretary)

This month the Native Orchid Society of South Australia celebrates its thirtieth “birthday”. A review of the first five years of the Society’s Newsletters/Journals (yes, they were newsletters in the earliest days) reveals some interesting points. By 1979 “A total of 110 species [of orchids] and 14 varieties” were accepted. The following are some interesting aspects about the knowledge of, and what was then current thinking about, our orchids at that time. It must be remembered that no comprehensive book on South Australian orchids existed in those days, especially not any field guides. The most useful “tools” the members had to work with were Blacks Flora of South Australia and W.H. Nicholls “Orchids of Australia”. In 1979 “A Checklist of Orchidaceae on South Australia” by J.Z. Weber: Changes introduced in the new ‘Black’s Flora” by R. Bates, appeared as a full issue of the Native Orchid Society of South Australia Journal.

Today we sometimes struggle to grasp all the fine differences when orchid species, or species groups, are split, but spare a thought for those wanting to identify with what they have seen in the field back in about 1979. An article by R. Bates describes the “Variations within the species Caladenia dilatata R.Br. in South Australia”. “There are, at present, two recognised varieties” viz. C. dilatata var. dilatata and C. dilatata var. concinna. Within these two varieties are further more divisions into distinct sub-varieties or races! At that time there were six distinct forms recognised; how much easier today, now that they are named as species. These would now include C. tentaculata, C. verrucosa, C. stricta, C. toxochila and C. conferta.

Orchid 1 Arachnorchis tentaculata
 Arachnorchis tentaculata (King spider Orchid)  syn Caladenia tentaculata

Recognition of what could be species has long been apparent. Take for example the article written in 1980 about two forms of Pterostylis nana, viz. what we commonly refer to as the ‘Hills’ form and the ‘Mallee’ form. This article documents the obvious morphological differences and illustrates this with line drawings and a map showing distributions of the two. Electronic Orchids of S.A. currently recognises five possible species of P. nana for South Australia. These are probably all un-named, since David Jones, in “Native Orchids of Australia”, does not recognise true P. nana in our state. Similarly, an article written in 1981 discusses the P. alatascabrarobusta complex. The author recognises there are “at least four species of this group in South Australia”. This is the first time the authors acknowledge they should be elevated to species, not just accepted as varieties or forms. At that time P. robusta was treated at varietal level, viz. P. scabra var. robusta or P. alata var. robusta. Ultimately most of these have been elevated to species level (P. dolichochila, P. erythroconcha, P. robusta, and P. striata).

It was noted that in 1978 David Jones and Ray Nash were currently working on Pterostylis. Further to that Les Nesbitt notes that of the sixty or so Pterostylis in Australia, South Australia has twenty-two species. One wonders what the count is now. It is well known that David Jones is currently/still working on the Pterostylis group, with more species being recognised regularly.

Thelymitra x irregularis
Thelymitra x irregularis or Pink Spotted Sun Orchid was photographed in 2009 near Macclesfield

In a series of articles produced about “Our rarest orchids” in 1977 we find the comment “Very few of our orchids are thought to be extinct… . “One wonders what that number would be considered to be today. The same article talks about the demise of Pterostylis cucullata and the possibility that it may no longer exist in the wild. Certainly this is one of our highly endangered species for which recovery actions are being undertaken these days. [N.O.S.S.A. members have an opportunity to assist with this work starting on April 14th – see diary dates.] In 1977 there was excitement when, following a field trip to Belair National Park one member returned the following day and “the elusive Pterostylis cucullata” was seen “growing in association with P. curta”. In 1981, following a discussion and review of endangered orchids in South Australia, R. Bates writes “There are a number of endangered species in S.A. which have not yet been named. It is not unlikely that some of these will become extinct before they are even described properly.” With such a large number of as yet undescribed orchids in our state, let us hope this does not happen.

Naturally occurring hybrids and the naming of such, has been debated regularly within botanical circles. In 1978 this insight is shown by Ray Nash who “guided us to a nearby patch of Thelymitra macmillanii,…… Ray’s view is that this will probably turn out to be a hybrid, possibly between antennifera (which it closely resembles) and rubra or luteocilium.” In 1980 T. decora [T. x truncata] was featured as one of South Australia’s rarest orchids. It was thought to be of hybrid origin and three forms were recognised then. The probable parents were T. ixioides x T. longifolia, T. ixioides x T. pauciflora, and T. ixioides x T. mucida. Today with the naming of many species within the T. pauciflora complex, it is now being recognised that there are even more combinations producing similar type flowers, e.g. T. juncifolia, which gives rise to the spotted features, x T. brevifolia.

Name changes always raise controversy. A brief explanation giving some insight into this complex area can be picked up when an author is expanding on the front cover illustration of Corybas. “In fact, they should never have been called Corybas in the first place. They were discovered by Robert Brown during the Flinders Expedition (1801 – 1805), and illustrated by the Austrian Ferdinand Bauer, another of the members of the expedition. Brown called them Corysanthes from the Greek “korys” (a helmet) and “anthos” (a flower), and they were known for many years by that name. However, in this instance, justice was never truly done, because the decision was made to call them Corybas, the name previously allotted by R.A. Salisbury in 1805, on the strength of seeing Bauer’s illustrations.” More recent times have seen that injustice righted with the name reverting to Corysanthes, something brought about through the work of David Jones. Similarly, the latest naming of Corunastylis tepperi follows this, The International Code of Botanical Nomenclature, a name that was recognised by R. Bates in an article written in 1981! However, Bates concludes that P. tepperi and P. nigricans are synonymous, so the latter prevails, but “further work needs to be done”! He is also the author of an article depicting some name changes in 1980. If our readers are confused by “new” names, then just think what it was like for those in 1980 when, among others, Caladenia carnea, and all its five varieties, is changed to C. catenata, with all its varieties, two of which are C. catenata var. gigantea and C. catenata var. minor. Two others were elevated to C. pusilla and C. alba.

 

Corysanthes diemenica 077
Corysanthes diemenica (Veined Helmet Orchid)

At one time our esteemed orchidologist was asked to comment on a list of name changes being proposed for the revision of Black’s Flora of S.A. “My first reaction was to state that everyone would be happiest if no changes were made”! However, in fairness to that gentleman, it must be said that by the time he had worked through a lengthy consultation with botanists covering much of Australasia, a revision of type specimens and other material and associated literature, he was clearly of the opinion that the changes were warranted.

Have our orchids changed? Maybe, but what has really changed is our knowledge and understanding of these unique plants. Based on that knowledge, opinions, attitudes and ideas have changed. Thirty years ago it was not “policy to differentiate between the numerous forms of C. patersonii in this State …” Today we have numerous named species in this complex, without actually any Caladenia patersonii as such.

The final word must come from Peter Hornsby when he said “The ultimate aim should be for the reader to know which plant is being discussed, rather than whether or not the title is absolutely correct.”

References:

Native Orchid Society of South Australia Journal.

1. 1977 Vol. 1 #5 2. Vol. 1 #9 3. 1978 Vol. 2 #2 4. Vol. 2 #6
5. Vol. 2 #7 6. 1979 Vol. 3 #1 7. Vol. 3 #6 8. Vol. 3 #9
10. 1980 Vol. 4. #3 11. Vol. 4 #4 12. Vol. 4 #6 13. Vol. 4 #7
14. 1981 Vol. 5 #1 15. Vol. 5 #3 16. Vol. 5 #4 17. Vol. 5 #6

Black J.M. 1978. Flora of South Australia, Part 1, Third Edition. Handbooks Committee, South Australia.

Jones David L. 2006. A Complete Guide to Native Orchids of Australia, Including the Island Territories. Reed New Holland, Australia.

Nicholls, W. H. 1969. Orchids of Australia; The Complete Edition. Thomas Nelson, Australia.

Gleanings From the Journal: Rescuing apparently ‘dead’ orchids Parts 2 & 3 of Three Parts

This week we continue with both Part Two and Part Three of Brendan Killen’s Rescuing Apparently ‘Dead’ Orchids  which appeared in the Volume 31 No 9 October 2007 and Volume 31 Bi 11 December 2007, respectively.

Rescuing apparently ‘dead’ orchids. Part 2 By Brendan Killen

PLANT #2 – Dendrobium Alick Dockrill “Pale Face”

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The cane pieces of this plant were inserted into a bark mix at the same time as the canes of Den. Jayden ‘JANE’ [See the July Journal] were inserted into sphagnum moss. The outcome is three healthy growths.

Note the dried ends of the canes where they were cut into separate pieces. As you can see from the photograph, I used a green twisty to hold the canes in the bark as a fairly solid bunch – I find this is the best way to keep the canes still whilst they are developing sensitive new growths. I have found that no matter how bunched-up the canes are, the new growths always find a way to the surface.

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Here is a different angle on the new growths with my fingers providing some perspective on the size of the growths.

Note that they are significantly larger that those on the Den Jayden ‘JANE’, with the same time in the pots.

I do not consider this evidence of the worth of bark compared to sphagnum moss.

I find that different hybrids and species behave quite differently in terms of their speed and timing of production of new growths. I believe that it is a function of what species are in the background of these plants and the time of year the rescue is undertaken.

Here is the same plant 5 weeks later. The new roots are protruding from the pot and the new growths are extending themselves – all of this at a time where severe water restrictions limit me to two waterings each week by watering can!

Plant 2-3 Den Alick dockrill 'Pale Face'.jpg

Plant 2-4 Den Alick dockrill 'Pale Face'.jpg

A further 4 weeks of cultivation and bright, warm weather has fully extended and hardened the new growths.

The larger growth should produce a flower spike this Spring.

Dendrobium Alick Docrill “Pale Face” (Photographer: Josh Bridge)

TO BE CONTINUED

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 Rescuing apparently ‘dead’ orchids. Part 3

By Brendan Killen

Plant #3 – Dendrobium Sarah Jane ‘Purvis’

This is a plant that the late John Purvis gave me just before he passed away. Because it is a special plant to me, I cut an old cane into three pieces to produce a back-up plant, just in case my piece of the original fell foul of the orchid gremlins.

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As you can see, it is the least developed of the three plants featured in this article. And yet, the parent plant has produced two magnificent new growths in the same period. I feel that the 12.5% of Den. bigibbum and 12.5% of the hot growing Den. tetragonum var. giganteum have influenced this. This new growth has probably been encouraged since the relocation from Adelaide to Brisbane where the temperature differences overnight are more subtle than in the Adelaide Hills where the plants were previously cultivated. The two hot growing species in the plant’s background were probably held back by Adelaide’s much cooler overnight temperatures. Anyway, this is purely conjecture on my behalf. What is important is that I now have a developing back-up plant for one that I treasure dearly.

Dendrobium Sarah Jane ‘Purvis’ (Photographer Josh Bridge)

SUMMARY

The thrust of what I have written is simple – don’t give up on treasured plants that look like they have expired, because there is always hope so long as the canes haven’t turned into fermented mush! The technique is as simple as cutting canes into lengths where you have at least three, preferably four, segments from which new growths will materialise. Use sterilized cutting tools to avoid contamination of the canes. Once the new growths have emerged, give them time to produce healthy root systems and let the new canes harden before potting-on. The best time I have found to pot-on the new growths is early autumn.

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Thank you to Josh Bridge for supplying images of the flowers of Dendrobium Alick Dockrill “Pale Face” and Dendrobium Sarah Jane ‘Purvis’ as they were not in the original articles.

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Another technique demonstrated by John Gay at one of the NOSSA meetings a couple of years ago was to take the apparently dead canes of an epiphytic orchid and seal them in a plastic bag with a small piece of damp sponge (or other cloth) and leave them in the shadehouse.  Do not let the sponge dry out.  So long as there was a bit of moisture, there was a chance for new growth on the shrivelled canes.  Once the growth was obvious, pot on as normal.

GLEANINGS FROM THE JOURNALS: Part 1 of 3 parts Rescuing apparently ‘dead’ orchids

The following is part of a three part series on reviving apparently dead epiphytic orchids from Volume 31 No6 July 2007

 

Rescuing Apparently ‘dead’ Orchids

By Brendan Killen

In late Spring 2006, I had an ‘open shade house’ event at my place in Belair, South Australia. As part of the programme, I demonstrated how I rescue orchids that have all but died. My demonstration was based on many years of experience in not giving in to the demons that cause orchids to expire.

I used two orchids that everyone attending agreed would normally be tossed into the rubbish bin or compost – all bare canes; heavily shrivelled; all new growth ‘eyes’ at the base of the canes chewed out by insects. In other words, an apparently hopeless situation. I’ve never given up on these terminal plants, believing that they still had life in the old canes along as they hadn’t turned to fermented mush.

I also used an apparently ‘dead’ cane from a treasured orchid that I was hoping would eventually produce a back-up plant using the method I describe in the following text.

In one case (Dendrobium Jayden), I cut the canes into a number of segments and stuck them into a pot with heavily compressed sphagnum moss, topped with river gravel to suppress the moss from growing and overtaking the pot. In the other two cases (Den. Alick Dockrill & Den. Sarah Jane), I cut the canes into segments and placed them in a pot of small composted bark.

The following photographs were taken about 3 months after the repotting demonstration and after the plants were relocated to Brisbane. They demonstrate the benefit of the right technique and a ‘don’t give up’ attitude. This technique has not failed me yet, allowing me to rescue many prized plants that have gone on to be show-bench winners.

PLANT #1 – Dendrobium Jayden “Jane”.

Plant 1-1 Den Jayden 'Jane'.jpg

This photo illustrates the emerging new growth on a Den. Jayden “Jane”. This is the first evidence that success is at hand. It is also the first new growth discovered on this plant before I inspect the canes further to see if there are any other new growths buried within the sphagnum moss.

Plant 1-2 Den Jayden 'Jane'.jpg

In this photo, you can see that the new growth is very pale from having emerged from deep in the sphagnum moss with little exposure to light. The juvenile roots can be seen emerging on the right hand side.

Plant 1-2-2 Den Jayden 'Jane'.jpg

A closer inspection reveals another growth, on the other side. Note that both growths are not coming from the ‘eyes’ at the bottom of the canes – simply because they were cut off at potting time. They are emerging from the section that joins the cane segments.

Plant 1-3 Den Jayden 'Jane'.jpg

Teasing away the sphagnum moss reveals even more of the young roots. Note how the new growths are lacking any colour substance at this stage.

If I were to ignore this plant for much longer, the new growths would have rotted in the very moist sphagnum moss, neutralising my efforts. So, the lesson here is to ensure that you monitor the plants for new growths and ensure that you elevate the new growths above the sphagnum moss to give them a chance to ‘harden off’ from their immersion deeper in the sphagnum.

Plant 1-4 Den Jayden 'Jane'.jpg

This photo illustrates how I have re-seated the canes within the sphagnum moss, but much higher so that only the roots are exposed to the heavy moisture content of the moss. I choose to do this instead of placing them straight into a bark mix as I find that the plants tend to go into a shock at the relative lack of moisture in bark and can die quickly, or suffer from stunted growth. I wait until the new growths have matured with substantial green substance before I repot them in a bark mix. And, I tend to do this in late autumn when they are not under any temperature or light stress. By spring, they will be racing ahead in the bark mix with new root growth and, possibly new canes and/or flower spikes.

One Month Later……….

Plant 1-5 Den Jayden 'Jane'.jpg

After one month from the re-seating described previously, note that the pale new growth is now mature and bright green. And, note how the roots are emerging from the growth above the sphagnum moss. This plant will be ready for potting-on into a bark medium in the next few weeks as autumn cools the air in Brisbane.

Plant 1-6 Den Jayden 'Jane'.jpg
Den Jayden ‘JANE’ in flower

This is how I expect it to flower in spring

TO BE CONTINUED …..