The process may have taken awhile, (for some longer than than the two years collaboration with the University of Adelaide,) but finally the Wild Orchid Watch app is now available for all Australians to use.
So why orchids…
Orchids are iconic and somewhat mysterious plants that are highly valued by sections of our society.
They are sensitive to environmental change most of which puts the survival of populations at risk of being lost permanently.
Orchids tend to be indicators of ecosystem health.
They are dependent on other parts of the ecosystem such as fungi within the soil and particular insect pollinators .
These insects are also dependent on a functioning ecosystem for their survival.
Thus, when orchids are conserved other parts of the ecosystem are also conserved resulting in broader benefits to the ecosystem as a whole.
So, why an app …
traditional methods of data collection for orchids are inadequate because of their
differences in emergence with seasons
short flowering, sometimes non-flowering, seasons
allows the collection of a wealth of knowledge known to orchid enthusiasts
this method of collecting data enables researchers to gain a better understanding of
the conservation status and trend of orchids
the value of orchids as indicators of environmental change
the phenology (life cycle), distribution and abundance of orchids
The WOW app allows citizens scientists to provide important data for researchers.
Bonus Benefit of the App – Identification
Probably one of the most frustrating things for the novice is not knowing what is the species of orchid that they have found. With this app it is not necessary to be familiar with all the orchid species.
The WOW app uses the iNaturalist platform where there is a whole community ready to assist with identification.
One can be an orchid citizen scientist without a detailed knowledge of orchids.
So, hop over to the WOW website to find more information, instructions and download the app.
The following article has been adapted from the 2019 July Winning Photograph
The July competition resulted in a draw. This article will concentrate upon only one of the winner’s – Lisa Incoll’s photograph of a Diplodium sp. found in the Southern Lofty Ranges.
Sometimes images are sent through unnamed or with only the genus named as in the case of Lisa’s picture. Unfortunately, it is not always possible to determine the identity from only one photograph beyond the genus level. In this case it can be seen that it is a Pterostylis but since the introduction of a segregate genera it is possible to narrow it down further to Diplodium sp.
Since there are two main Diplodium found in the Adelaide Hills (D. robustum and D. sp Adelaide Hills), I thought it would be a good opportunity to compare these two species.
The phrase name D. sp Adelaide Hills is used to distinguish it from D. alatum (syn. Pterostylis alata) which is considered to be endemic to Tasmania. The mainland species P. striata was previously known as P. alata. The eFlora-SA, the Adelaide Herbarium online key and census of the SA Flora has D. sp Adelaide Hills listed as P. alata (syn D. alatum).
D. sp Adelaide Hills and D. robustum share many similar feeatures. In the dichotomous fey found on the eFlora-SA, the separation between the two is primarily based upon size. D. sp Adleaide Hills is generally a taller-stemmed plant with a smaller flower and smaller, more slender cauline leaves. D. robustum is mainly a larger flower on a shorter stem. However there is an overlap between D. robustum and small specimens of D. sp Adleaide Hills which can make determination of species difficult.
Based upon the descriptions and the key from eFlora-SA, Orchids of South Australia (1990) and South Australian Native Orchids (2011), the following table shows the similaritites and differences between the two species. For completeness, shared features (highlighted in bold) are also included.
Diplodium robustum (syn. Pterostylis robusta)
Diplodium sp Adelaide Hills (syn. D. alatum, P. alata)
5-20cm tall (usually less than 10cm tall); robust stem
8-25 cm tall; slender stem
6 – 7 ovate or elliptic-ovate (ie range from oval to egg-shaped) leaves in rosettes on long petioles
3 – 8 ovate leaves in small rosettes on long petioles
No rosettes or basal leaves
No rosettes or basal leaves
Alternating leaves clasping the base & increasing in size from the base upwards. Acuminate (long drawn out point)
Alternating leaves clasping the base & increasing in size from the base upwards. Acuminate
Broad (up to 8mm wide) lanceolate serrulate (tiny teeth) cauline leaves more than 3cm long
Slender lanceolate, cauline leaves less than 3cm long
Blooms can last up to 8 weeks in sheltered places
Delicate flowers can soon collapse with strong drying winds
Bright green & white with deeper green, longitudinal stripes
Pale-green or white with darker striations
Erect; bulbous near the base
Erect; bulbous near the base
Length 25 – 45 mm; diameter more than 20 mm; gradually curved forward at the apex
Length 20 – 25 mm long; Diameter less than 18 mm; gradually incurved
Ends in a long fine point to 5 mm long
Apex blunt; ends in a short fine point
Blunt or acute
Erect; conjoined basally; distally, the tips produced into long filiform erect points, embracing the galea & greatly exceeding it
Erect; conjoined basally; distally, the tips produced into long filiform erect points, embracing the galea & greatly exceeding it
Sinus (region where lateral sepals separate)
Flat, with a wide, shallow central v-notch; protruding in a shallow curve whenviewed from the side
Narrow sinus, with a notch in the middle; not bulging
Movable claw; nearly straight
Movable claw; nearly straight
Recaches height of the column
Slightly exceeding the height of the column
Forms small to extensive colonies
Forms small to extensive colonies
in rocky places; forest or scrublands
in rocky or shady locations; forest or forest heathlands
Mt Lofty Ranges
Mt Lofty Ranges
Flinders Ranges; Eyre Peninsula; Yorke Pensinsula; Upper South East
Kangaroo Island; South East; possibly Eyre Peninsula
Greater than 250 mm
Greater than 600 mm
May – September
May – July
Of course, as these two hybridise, that will complicate things, Hybrids will have characteristics of both parents but, with hybrid vigour; and vigour is one of the separating features between the two!
Shane Grave’s winning photograph for April was the spring flowering Caladenia plicata which is endemic to the South West of Western Australia.
Caladenia is a very large genus with over 330 species, 39 of these currently unnamed. In addition, there are 58 named subspecies and varieties. Caladenia plicata would belong under the subgenus Calonema or the segregate genus Arachnorchis which, although not generally recognised by State herbaria is commonly accepted by many amateur enthusiasts. Yet even this subdivision is still large with 192 species. As a result, some authors have created further groups/complexes, for example C. dilatata complex, C.longicauda complex, etc. However, according to Andrew Brown, C. plicata doesn’t seem to fit neatly into any of these categories, although David Jones does include it within the clubbed spider orchids.
Various authors consistently refer to the labellum as being unusual. In Fitzgerald’s formal description (1882) he states that the labellum tip is “recurved so as to become plicate and touch the under surface of the disc”. Plicate means to fold. The labellum tip of many other Arachnorchis species are known to curl under but none fold under in the way that this species does. The sharp fold with the spreading horizontal fringed margins (edges) combined with a central band of tall dense calli (wart-like structures) gives a distinctive shape reminiscence of a crab, hence the common name Crab Lipped Spider Orchid. The effect of this is best seen from a front, rather than a side, view.
The very mobile labellum is sufficient to identify this species, but it is also possible to identify when in bud “due to the prominent short osmophores (clubs) on the sepals”. The sepals narrow halfway along to form thick brown clubs and when the flower is open both the lateral sepals and petals are downswept. This is clearly seen in Shane’s photograph.
The winning photograph for March 2019, was Corunasylis ciliata (syn Genoplesium ciliatum). As with so many orchids, it has undergone a few name changes. Originally Prasophyllum, then Genoplesium and currently Corunastylis
Although Genoplesium was split into two with only one species remaining in Genoplesium and the others placed into Corunastylis, this split has not been accepted by the everyone. For example, eflora of SA and PlantNET use Genoplesium whilst VicFlora uses Corunastylis.
Whilst researching C. ciliatum I came across images of Prasophyllum spp. being misidentified as Corunastylis spp. and as it was originally described in Prasophyllum it seems appropriate to examine the similarities and differences between the two genera.
In South Australia (SA), the most obvious difference would appear to be size but across the rest of the country some Prasophyllum species potentially can be similar in size to the much smaller Corunastylis, although Corunastylis species are never as large as many of the Prasophyllum species.
Some of the shared features of the two genera are
multi-flowered on a single stem
single tubular leaf
flowers non-resupinate, that is the labellum is above the column and the dorsal sepal is below (the only other non-resupinate flowered orchids in SA are Gastrodia, Caleana, including Paracaleana, and Cryptostylis subulata)
Grow as scattered individuals
Tends to be a larger plant (up to 150cm), but can sometimes be as small as Corunastylis
Always a small plant (maximum no more than 90mm)
Leaf sheaf opens well below the inflorescence (flower head)
Leaf sheaf opens at the base of the inflorescence.
Often withered at flowering
Not withered at flowering
Usually curved backwards (recurved) resulting in an upright appearance of the flower.
Not recurved resulting in a more drooping appearance of the flower
Mainly spring flowering
Mainly autumn flowering
Jones DL A Complete Guide to Native Orchids of Australia including the Island Territories 2006
Prasophyllum and Corunastylis descriptions from VicFlora, accessed 1 May 2029
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.
Guest 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.
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
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.
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.
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.
Welcome to our first competition for 2019. For February we had five entries which included Pauline Meyers’ Prasophyllum species from Western Australia, Lindy McCallum’s Glossodia major and Leptoceras menziesii, Lisa Incoll’s Thelymitra antennifera.
The winner was Rob Pauley’s photograph from the south east of Thelymitra malvina (Mauve Tufted Sun Orchid) which is found in only a few places in the South East but does occur in Victoria, New South Wales, Queensland, Tasmania and even ‘across the ditch’ in New Zealand where it is considered “an Australian species now established in the North Island”.
According to the Atlas of Living Australia, it is endangered in Victoria, South Australia, Tasmania; of Least Concern in Queensland and there is no listing for New South Wales.
This species has been included in both the T. nuda and T. pauciflora complex for, as Jeanes has observed, it has characteristics of both complexes such as the smaller flowering forms are self-pollinating, and the larger flowering forms are insect pollinated
Though the common name, Mauve Tufted Sun Orchid, indicates that its most distinctive feature are the purple tufts on the post anther lobe, it is possible to find them with white tufts and there are other species that have purple tufts (eg in SA T. azure and T. occidentalis may have purple tufts but it is obvious from their other features that they are not at all similar to T. malvina). There are no other closely similar species in South Australia, but on the other hand, in the eastern states, it can be confused with Thelymitra atronitida, so it is worthwhile considering some of the main differences between these two.
Although there are no other closely similar species in SA, in the eastern states it can be confused with Thelymitra atronitida, so it is worthwhile considering the differences
3 sterile bracts
2 sterile bracts
25 – 75 cms
30 – 50 cm
Slightly larger (but can have smaller flowers)
3 – 25 usually loose
2 – 8 ( – 16)
Reddish to dark brown with yellow apex
Glossy black with yellow apex
Post anther lobe
Moplike tuft of pink or mauve (rarely white) trichomes
Moplike tuft of white trichomes (hairs)
Across the country, there is some variations of flowering times with New South Wales having the longest flowering time from August to November and South Australia along with Tasmania having the shortest of October and November.
Bates RJ, 2011 South Australia’s Native Orchids, electronic
Backhouse G, Bush Gems, A Guide to the Wild Orchids of Victoria, Australia, 2016, electronic
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.
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.
Every year, NOSSA holds monthly photograph competitions. This year, NOSSA decided to give the entrants an opportunity for their photographs to appear on a calendar. There have been 51 entries this year, so we are asking people to vote for the twelve images that they would like to see in a calendar.
Select the numbers corresponding to the twelve images that you would most like to see in your calendar
Indicate if you are interested in purchasing a calendar
This week’s blog is from the Journal of the Native Orchid Society of South Australia, Volume 42 No 8. Leo Davis has been doing a series of articles aimed at helping members learn how to identify the orchids.
This article is about Plumatichilos, one of the segregate genera of Pterostylis. It has an unique labellum which sets it apart from the other Greenhoods. Leo wrote this article soon after David Jones named them in the Australian Orchid Review. Will these names be accepted or not is a matter of waiting and seeing but it should be noted that they have been in manuscript form for many years. At the time of writing, they are not in the South Australian eflora.
Both the species discussed in Leo’s articles are from the Plumatiochilos plumosum complex or group.
Plumatichilos sp. Woodland Bearded Greenhood = P. foliaceus
Unless otherwise noted, all images are Leo Davis.
Back in 1990 Bates & Weber placed all greenhood orchids in genus Pterostylis(1. pp118-143) where some of you and all Australian State Herbaria and certainly Janes & Duretto (3. pp260-269) would have them still be. In 2001 Szlachetko erected the genus Plumatichilos. In his Guide(4. pp286-339), Jones divided the greenhoods into 16 separate genera, these in two groups, each of eight genera. One group all have the lateral sepals directed downwards (including Bunochilus and Urochilus) and the other eight all have them directed upwards (deflexed, as in Diplodium and Pterostylis). Even those of you who reject the splitting and creation of the extra genera will concede that those placed in Plumatichilos, which have downward directed and partly fused lateral sepals (forming a synsepalum), are strikingly different in appearance to any other Pterostylis species. The most obvious distinguishing features are the unique labellum and the two openings to the galea.
I had known just two species of Plumatichilos, both of which were undescribed. I could recognise and distinguish them essentially because they grew in very different habitats and locations. I used Bates’ tag names, Mallee Bearded Greenhood (Plumatichilos sp. Mallee Bearded Greenhood) (3. pp913-4) and Woodland Plumed or Bearded Greenhood (Plumatichilos sp. Woodland Bearded Greenhood)(1. pp915-916).In recent weeks both (along with two other South Australian species) have been formally described. They are now, respectively, Plumatichilos multisignatus(5. pp33-35) (Fig. 1) and P. foliaceus(5. pp30-32) (Fig. 2). But, to a large extent, I still identify them more by the locations in which I find them than, to my eye, clearly discernable physical features.
Fig 2. Plumatichilos foliaceus. Para Wirra. Sept 11, 2013.
I had no idea what ‘barrier trichomes’ were but I saw that Jones listed them as the last of 13 dot pointed characters of genus Plumatichilos(5. p26). Trichome simply means a hair growing from a plant epidermis. They can be unicellar or multicellular and branched or unbranched. The ‘barrier’ refers to its capacity to block and direct a pollinating insect to an exit path that puts it in the right posture to transfer a pollinium to the stigma (sticky receptive female part of flower).
Janes & Duretto, who reject the splitting of genus Pterostylis, divide it into two subgenera using the absence (subgenus Pterostylis) or the presence (subgenus Oligochaetochilus) of barrier trichomes on the column wings(3. pp262). They place what I call Plumatichilos in the section V, Catochilus, of subgenus 2 Oligochaetochilus(3. pp266), and, yes, I see your eyes glaze over. To them the Adelaide Hills ‘plum’ would be Pterostylis, subg. 2 Oligochaetochilus, Sec. V. Catochilus, species foliaceus. Learning what ‘barrier trichomes’ are had me go back searching my photo library and I found images of the barrier trichomes in Bunochilus flowers that I had not previously spotted. I have used and annotated a detail sent to me by June Niejalke. (see Fig. 3).
Fig. 3. Bunochilus prasinus. Sherlock (Type location for the species). Photo by June Niejalke.
As with all ‘true’ Pterostylis, the dorsal sepal and the two lateral petals, of the upside down flowers, are formed into a galea or cap (Fig. 1). They are fused so closely that it can be hard to discern the join between the sepal and the comparatively small petals, especially in some less clearly striped flowers. (Figs. 1 & 2).
The typical Pterostylis galea has a single opening but in Plumatichilos there are two, a lower one, from which the uniquely formed labellum protrudes (and through which the pollinating male gnats enter) and an upper one (through which the pollinators exit) (4. p335), guided by the barrier trichomes (Fig. 4). Through this upper opening you can observe the top of the column, including parts of it, the pollinia, the barrier trichomes, column arms and sometimes the stigma. Two crossed filaments, in front to the pollinia, are column arms.
Fig. 4. Plumatichilos foliaceus. Scott Creek C.P. Sept 2015.
The labellum (the modified third petal) (Figs 1, 2 & 5) is unlike that of any other Pterostylis sp. It has a slightly flattened filament having a reddish-brown apical knob and two or three types of hairs along its length. Jones describes the labellum of P. foliaceus as having three types of hairs(5. p30). You may be able to see the short white ones (1 mm) at the base of the labellum in Fig. 5. The longer (5-7 mm) yellow ones along the most of the length of the labellum are easy to see. I am not sure that I can distinguish the shorter proximal (near point of attachment) yellow ones (1.5 mm). In P. multisignatus Jones describes just two types of labellum hairs(5. p33) with the white basal ones absent, and two sorts yellow hairs, proximal ones to 1.2 mm and longer ones 5-8 mm. To my eye, this character, two or three types of labellum hairs, is the only objective, rather than subjective , distinguishing feature between the two species that I regularly observe.
Fig. 5. Plumatichilos foliaceus. Scott Creek C.P. Sept 26, 2015.
In Fig. 5, I think that you can see that the hairs arise, in two parallel rows, not paired, from the sides of the flattened shaft of the labellum filament.
Fig. 6. Plumatichilos foliaceus in early bud. Scott Creek C.P. August 29, 2018.
Another generic character is ‘leaves sessile (no stems), ascending to erect, often with whitish or yellowishinterveinal areas.’ (5. p26) You may need to look very closely, in Fig. 6, to see these ‘windows’, mainly at the bases of the stemless leaves.
Bates, R.J (2011). South Australian Native Orchids, DVD Issued by the Subediting Committee (NOSSA) on behalf of the Native Orchid Society of South Australia Incorporated. 2. Bates, R.J. & Weber. J.Z (1990). Orchids of South Australia, A. B. Caudell, Government Printer, South Australia.
Janes, J.K. & Duretto, M.F. (2010), A new classification for subtribe Pterostylidinae (Orchidaceae), reaffirming Pterostylis in the broad sense. Australian Systematic Botany, 23, 260–269.
Jones, D.L. (2006), A Complete Guide to the Native Orchids of Australia, Reed New Holland, Australia. 5. Jones, D.L. (2018), Six new species of Plumatichilos (Orchidaceae: Pterostylidinae) fromSouth-eastern Australia and a new species from New Zealand, Australian Orchid Review 83(4): 26-44.
Other articles about Plumatochilos can be found here and here.
The following article is the beginning of a series of discussions on identifying features of various orchid species/genera.
A previous blog (see here) referred to the importance of the column in Thelymitra but did not give details of the parts of the column which is the subject of this blog.
The columns in a Thelymitra (Sun Orchid) may be one of the main identifying features of a sun orchid and so this article looks at those features that botanists will often refer to in their descriptions.
Though we cannot physically dissect an individual flower, we can make use of photographs to spot the various features.
The diagram below is that of T. ixioides (based on the taxonomy of 1984) column whilst the photographs are that of T. juncifolia column (as T. ixioides is now considered to be limited to the eastern states). The column of these two are similar. One photograph will not give all of the features hence in this article the three photographs show all of the features except the viscid disk where the pollinia is stored. The stigmatic plate is sticky and receives the pollen for fertilization.
Most of the variations between the Thelymitra columns occur within the upper portion of the column. The post anther lobe can be quite varied. For instance, with T. ixioides/T. juncifolia the post anther lobe is not hooded. Some with hoods may have deep splits, whilst others form a broad fringe. Yet again, others have variations within the column arms such as having no cilia. This will be dealt with in further articles.