Petalochilus – when use of a segregate or common name is helpful

The following article is from the Native Orchid Society of South Australia Journal Volume 44 No 7, author Rosalie Lawrence.

Over the years there have been many orchid name changes (particularly at genus level), some quite drastic, some multiple times and for many there can be a reversion back. Yes, this creates confusion but there are times when some of these name changes, known as segregates (both at species and genus level) can be useful.

Caladenia carnea (synonym Petalochilus carneus) Photographer Lindsay Ames

A case in point, is Lindsay Ames’ winning photograph (June) – Caladenia carnea synonym Petalochilus carneus. Petalochilus was proposed as a genus in 2001 by DL Jones, MA Clements, et al. It was one of many proposed genera changes. Many discussion papers followed but in 2015 after further taxonomic and DNA work, Mark Clements et al published a paper that “points to Lindley’s 1840 interpretation of Caladenia (…..) as being the most accurate reflection of the group.” Hence the discontinued use of Petalochilus and the other segregate genera.

So, it currently belongs with Caladenia, a large genus with over 350 species (mainly in Australia). It is a genus with great morphological (visual) diversity – compare Caladenia tentaculata with C. cucullata or C. flava. But Caladenia
subgenera Caladenia (synonym Petalochilus*), as a much smaller segregate genus allows us to visualize a specific group within the Caladenia genus.

Caladenia flava Photographer Pauline Meyer

Caladenia sens. lat. are characterised by single hairy leaf, lacking lobes or serrations; hairy stem; showy flowers with similar sepals & petals. The labellum is highly modified consisting of three lobes with calli on the middle lobe.

Caladenia tentaculata (synonym Arachnorchis tentaculata) Photographer Jane Higgs

Petalochilus is further characterised by small (1 – 5 cm) pink to white flowers,
short broad forward projecting tepals; erect to slightly incurved dorsal sepal,
distinct trilobe labellum, hinged, with calli and red transverse bars, column
green to pink with red to purple bars.

Caladenia carnea (synonym Petalochilus carneus) Photographer: Rob Pauley

Yet within Petalochilus itself there can be further groupings of which P carneus is most likely the main one. This consists of at least 8 species – P carneus (C carnea), P catenatus (C catenata), P coactilis (C coactilis), P fuscatus (C fuscata), P ornatus (C ornata), P prolatus (C prolata) , P. vulgaris (C vulgaris) and P xantholeucus (C xantholeuca). When a specimen cannot be identified to species level, it may be helpful to refer to it as a complex.

This is where comes the fun of trying to identify the specific species in the field (or for that matter from a photograph). To help myself understand, I often produce comparison charts based on descriptions found in the literature. The chart comparing the eight species is available as a pdf.

Caladenia prolata (Petalochilus prolatus) Photographer: Helen Lawrence

*Throughout the article the synonym Petalochilus is used for Caladenia subgenera Caladenia to make a clear distinction from Caladenia sens lat. It needs
to be noted C carnea is considered the type specimen for Caladenia so with any splits, it will remain in Caladenia.

References

Backhouse G et al,Bush Gems: a guide to the Wild Orchids of Victoria 2016
Bates R B South Australia’s Native Orchids 2011
Clements MA, et al, Caladenia Revisited: Results of Molecular Phylogenetic Analyses of Caladeniinae Plastid and Nuclear Loci 2015
Jones DJ, A Complete Guide to Australian Orchids including it Territories and Islands 2006
https://en.wikipedia.org/wiki/Caladenia Accessed 3 August 2020
https://www.pacificbulbsociety.org/pbswiki/index.php/Petalochilus Accessed 3 August 2020

Thank you to Andrew Brown for reviewing this article.

South Australia’s Arachnorchis cardiochila

The following article, March Winning Photograph, is from Volume 44 no 4, May 2020 Native Orchid Society of South Australia Journal.

Pauline Myers’ Arachnorchis cardiochila was the winning picture. Synonyms for Arachnorchis cardiochila are Caladenia cardiochila, Phlebochilus cardiochilus and Caladenia tessellata. Common names include Heart Lipped Spider Orchid, Thick Lipped Spider Orchid, Fleshy Lipped Caladenia.

This species was named in 1886 by Professor Tate who presented it at the Royal Society of South australia at the October meeting. He did the original drawing.

The type specimen was collected at Golden Grove on October 2 1886 but it had also been collected much earlier (1865) at Barraba Scrub which is in the region of Mallalla.

Its fate in both these areas has not been good; it is extinct in Golden Grove and critically endangered in the region containing Barabba Scrub. Although, it is considered to be a reasonably common orchid throughout its range in South Australia, Victoria and Southern New South Wales, there are areas of concern as seen the Seedbank of South Australia map below.

It should be noted that though Caladenia tessallata is listed as a synonym that this was used incorrectly, as C. tessallata is a separate but similar species found in the eastern states. Its main difference from C. cardiochila is that the edge of the labellum (lip) is toothed, not smooth as seen in Pauline’s photo.

Terrestrial Culture – December & January

The following two articles are from the December 2019 NOSSA Journal. Written by Les Nesbitt, they cover the months of December and January.

Terrestrial Culture – December

A few late orchids such as Diuris drummondii may still have green leaves and flowers so will need watering every couple of days. Most terrestrials will have died down by now on the Adelaide Plain. Watering consists of a quick squirt with the hose once a week to moisten the top 1 cm to prevent tubers shrivelling. A small terrestrial collection of pots can be moved to a cooler place out of direct sun under a bench or to the south side of the house. A large collection must stay on the benches so extra shadecloth is added for the summer.

Repotting is in full swing now. Keep a stock of the required materials on hand including sand, soil, native potting mix, clay, blood & bone, chopped sheoak needles, smashed and sieved gum leaves pots labels, shadecloth squares for crocking, pencils to write on plastic, sieve and bowl, watering can & shadehouse benching. A system for washing and sterilizing pots before reuse is essential to control disease and virus.

Pots dry out quickly in hot windy weather. Water a day or two before repotting so that the potting mix is just moist. If too dry dust will be a problem and tubers can be damaged by hard lumps of mix. Too wet and the mix sticks to the tubers and clogs the sieve. The ideal is a mix that is easy to work when separating wet pots take tubers from mix. It helps to move some pots under cover in case of rain. Wet pots take several days to dry out which can hold up repotting. Alternatively, a sheet of plastic over the pots when rain is forecast will shed the water but remember to weigh it down with bricks or it will blow away.

Pick out the tubers and put them in a kitchen sieve sitting in a container of water. Use a jet of water to wash the tubers clean and spread them on a towel to dry. Discard any tubers that are soft or have turned black. If the tubers are healthy, firm and a pale colour the mix can be reused. Colony type tubers should have at least doubled in number since last year. Add half fresh mix to the old mix and add a big pinch of blood & bone fertilizer. Should the old mix be dark in colour, or the tubers not be healthy looking then throw out the old mix and pot up in new mix.

Select the pot size, place a shadecloth square in the pot to retain the mix when it dries out. Fill the pot with mix to about 2cm from the top. Select the largest tubers for a show pot and push them into the mix with the shoot on top. The small tubers can be potted in another pot to grow bigger next year. Cover the tubers with more mix and almost fill the pot. Firm the mix down with your hand or use the bottom of an empty pot. Cover the surface with chopped sheoak needles. Write out a label with the name of the orchid and the provenance,
if known. On the back of the label note the number of tubers and the date planted. Water the pot gently so as to not disturb the needles. This helps settle the soil around the tubers and makes subsequent watering easier. Put the finished pots back in the shadehouse to await the next growing season.

Send off your tuber bank order before Christmas or you might miss out on your choices. The tuber bank is a great way to increase your terrestrial collection.*

*Tubers are sold only to financial members

Terrestrial Culture – January

Start watering the blue tag pots in January. Pots of orchids from the East Coast of Australia where it rains in Summer are given a blue tag as the culture is different compared to local terrestrial orchids. This early shooting group includes most cauline greenhoods, Pterostylis baptistii and Corybas hispidus. Local South Australian tubers can be kept completely dry until at least mid-February if pots are shaded.

When your tuber bank order arrives, pot up the tubers straight away. Plant each species in a separate 125mm or 150mm pot. Don’t forget to record the provenance name (if known) on the label and in your recording system. The
provenance is the location of the original collection. Provenance is important because in 10 years the orchid will possibly be extinct in that area as suburbia expands or weeds take over the habitat.

Summer watering is important. Too little and tubers may dry up. Too much and they may rot or come up early before the heat of summer is over when they will be attacked by thrip and aphids. A light sprinkle on top of the pots once a
week works OK.

Try to finish repotting this month. If left until February there is more chance of breaking off the new shoots which can be well developed by late February.

End with the Pods #1

In 2011, Robert Lawrence wrote a book titled Start with the Leaves, a beginners guide to orchids and lillies of the Adelaide Hills. Bob Bates, editor of South Australia’s Native Orchid 2011, suggested that the next title should be End with the Pods. Well another field guide has not been written but following Bob’s suggestion, it might be interesting to see how far one can go with orchid identification based upon the pods, or finished seed capsules.

As most of the orchids for the Adelaide Hills and Fleurieu Peninsula have finished, it might be worth a look at some capsules found this year and see how far we can go with identification.

Here is the first one:
These pictures were taken on a mobile phone on the 30th November, 2019 on the Fleurieu Peninsula. There were several plants with single pods scattered across the park. The stems were reasonably tall (est 30cm) and surprisingly easy to spot.

The habitat is open forest consisting of Eucalyptus leucoxylon (Blue Gum), E. baxteri (Brown Stringybark) and E. fasciculosa (Pink Gum).

Seed pod
Senensced leaf of the same plant above

Is there enough information to identify this plant to species level?
Comment on what you think it is and why.

Caged For A Reason

Sadly many of our orchids are under threat of extinction.

Fortunately, conservationists and researchers are putting in a lot of effort in an attempt to save them. Part of this work consists of caging and tagging individual plants.

Most people do the right thing and do not disturb the cages/tags. Unfortunately some, hopefully mainly through lack of knowledge, do move them. Sadly, too many of them are being moved. Sometimes they are re-positioned but not always.

There are a good reasons for the individual plants to be tagged/caged. And there are good reasons for not moving either the tags or the cages.

Tags

Tags are usually numbered. These numbered tags are reference locations from which the distance and bearing of plants are measured. If the pin is moved the record for that individual plant is invalidated. Position of pins are used to determine if plants reappear in succeeding years.

Replacing the pins can also result in inadvertently spearing, and thus destroying, the tubers.

Cages

Cages are used to protect individual plants from grazing. Moving cages, even if returned, can result in damage to the plant, as well as damage to any emerging juvenile plants.

NOSSA & Conservation

One of the main activities of NOSSA is conservation. Many of our members assist in the work of monitoring, caging and tagging of plants. They know of the time and effort required for this work. They know why it is important not to move tags or cages, not even for taking photographs.

But we are aware that there are those who do not know and so would ask that others pass this message onto friends who may be unaware of the significance of cages/tags.

So simply put, “Cages & tags are not to be moved under any circumstances”.

Diplodium robustum or Diplodium sp Adelaide Hills?

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)
Plant Height5-20cm tall (usually less than 10cm tall); robust stem8-25 cm tall; slender stem
Sterile plantsYesYes
Leaves6 – 7 ovate or elliptic-ovate (ie range from oval to egg-shaped) leaves in rosettes on long petioles3 – 8 ovate leaves in small rosettes on long petioles
Leaf edgesSmooth
Flowering PlantsNo rosettes or basal leaves No rosettes or basal leaves
Cauline LeavesAlternating 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 longSlender lanceolate, cauline leaves less than 3cm long
FLOWER
Blooms can last up to 8 weeks in sheltered placesDelicate flowers can soon collapse with strong drying winds
InflorescenceSingular flower Singular flower
ColourBright green & white with deeper green, longitudinal stripesPale-green or white with darker striations
GaleaErect; bulbous near the base Erect; bulbous near the base
Length 25 – 45 mm; diameter more than 20 mm; gradually curved forward at the apexLength 20 – 25 mm long; Diameter less than 18 mm; gradually incurved
Dorsal SepalEnds in a long fine point to 5 mm longApex blunt; ends in a short fine point
PetalsBluntBlunt or acute
Lateral SepalsErect; 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 sideNarrow sinus, with a notch in the middle; not bulging
LabellumMovable claw; nearly straight Movable claw; nearly straight
Dark greenGreenish
Erect potitionRecaches height of the columnSlightly exceeding the height of the column
ColumnColumn erect Column erect
HabitatForms small to extensive colonies Forms small to extensive colonies
in rocky places; forest or scrublandsin rocky or shady locations; forest or forest heathlands
RegionsMt Lofty Ranges Mt Lofty Ranges
Flinders Ranges; Eyre Peninsula; Yorke Pensinsula; Upper South EastKangaroo Island; South East; possibly Eyre Peninsula
Rainfall areaGreater than 250 mmGreater than 600 mm
Flowering TimeMay – SeptemberMay – 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!

References
http://flora.sa.gov.au/cgi-bin/speciesfacts_display.cgi?genus=Pterostylis&species=robusta Accessed 6 September 2019

http://flora.sa.gov.au/cgi-bin/speciesfacts_display.cgi?genus=Pterostylis&species=alata Accessed 6 September 2019

Bates RJ, 2011 South Australia’s Native Orchids, electronic

Bates RJ Weber JZ, 1990, Orchids of South Australia,

Monthly Terrestrial Orchid Culture – August

With Spring on the way, things are starting to change in the Orchid House. Here are Les Nesbitt’ notes from the August Journal 2019 Vol 43 No 7

Terrestrial Culture – August

The days are getting longer now, noticeably so after the middle of the month. When the clouds clear, the sun is stronger & higher in the sky. Temperatures increase and growth speeds up. Lots of buds are developing so there is plenty to see in the orchid house. The greenhoods are a feature with Pterostylis curta, nutans, pedunculata and their hybrids are all flowering.

Pests become more active. Look out for aphids on flower stems. Depending on the season deflasking can start after the middle of the month if a sunny and dry Spring is forecast, otherwise wait until September.

The NOSSA Spring show is only a month away. Start preparing your specimen pots for the display. Any spare pots can be sold on the trading table. There are never enough terrestrials on the trading table at the show to meet the demand.

Photograph your orchids when the flowers are at peak condition. Then hand pollinate a flower or two to get seed for the NOSSA Propagation Workshop or for sowing around mother plants next autumn. Prepare two pots of each species, one for showing and one for seed.

 

How to hand pollinate.

Look closely at the flower column to see the positions of the pollen and the stigmatic surface. Flowers can be self-pollinated if there is only one. Fatter pods with more viable seeds result if two plants of the same species are cross pollinated. That is transfer the pollen from one flower to a flower on another plant. Cross pollination mixes the gene pool to prevent inbreeding. Use a toothpick or a she-oak needle to touch the pollen which will stick to the wood. Wipe the pollen across the stigmatic surface of the other flower and the job is done.

If pollination is successful, the flower will collapse in a few days and the ovary will start to swell. For greenhoods the stigmatic surface is halfway up the front of the column. Remove the front of the flower and the lip so you can see what you are doing. Greenhoods have yellow pollen. For Diuris and Thelymitra the white pollen is hidden behind the sticky stigma. Caladenia have yellow pollen under flaps at the top of the column. Stroke upwards to open the flaps as would an insect backing out of the flower. The stigma is a hollow sticky depression just below the pollen. You will have to tip the flower right back to see it.

Selecting Photographs for 2020 NOSSA Calendar

It’s time to vote again!

Following the success of 2019 NOSSA calendar, we are continuing with the same format of inviting people to vote for the twelve orchids that they would like to see in the 2020 calendar.

All the entries are South Australian orchids that were from the NOSSA monthly photograph competition.

To enter:

  •  Select the numbers corresponding to the twelve images that you would most like to see in your calendar
  • Email your twleve votes – nossa.enquiries@gmail.com (Subject Heading – Calendar)
  • Voting closes on Friday 9 August 2019

The results will be collated to determine the twelve most popular images that will go into the calendar. We plan to have the calendars available for purchase at the NOSSA Spring Show, September.

If you would like more details or see the images in a higher resolution, use the above email address to contact NOSSA.

These calendars make great gifts to those who love flowers and are greatly appreciated by orchid enthusiasts not connected to a club.

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.

Selecting Photographs for 2019 NOSSA Calendar

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.

To vote

  • 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
  • Email – nossa.enquiries@gmail.com  (Subject Heading – Calendar)
  • Voting closes on Thursday 1 November 2018

The results will be collated to determine the twelve most popular images will go into the calendar. We plan to have the calendars available for purchase at the next meeting, Tuesday 27 November.

If you would like more details or see the images in a higher resolution, use the above email address to contact NOSSA.

2018 Thumbnails Photogrpahs for voting