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,

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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

2018 February Winning Photograph

1802 sm RP Caladenia carnea

A small but varied number of entries for our first competition of the year. Andrew Primer entered a lovely picture Thelymitra azurea from Eyre Peninsula; Thelma Bridle entered Calochilus cupreus one of South Australia’s endangered orchids; John Fennell’s close up of Caladenia prolata and Rob Pauley’s mass flowering of Caladenia carnea.

The winner was Rob Pauley’s C. carnea a wide spread orchid which ranges from across the Eyre Peninsula through to the South East as well as occurring in the Eastern States and Tasmania. Although considered common both nationally and at a state level, there are regions within its range where it is considered to be Near Threatened, Rare and even Vulnerable. Also, despite being common, the Seedbank notes that there are areas of probable decline: Fleurieu (KAN02), Mt Lofty Ranges (FLB01), Eyre Mallee (EYB05), Wimmera (MDD05) and Southern Yorke (EYB01). It is a reminder that not only the rarest species but also that common species can be in decline.

The situation is complicated by taxonomic issues; C. carnea is not only a highly variable species but also a complex of several similar species plus many undescribed species which continues to challenge botanists.

References:

http://saseedbank.com.au/species_information.php?rid=815 accessed 8 March 2018

Backhouse, G., et al, (2016) Bush Gems: A Guide to the Wild Orchids of Victoria, Australia, Electronic version.

Bates, R. J., ed. (2011). South Australian Native Orchids. Electronic version. NOSSA

2017 October Winning Picture

1710 JH Arachnorchis tentaculata sm

This month’s theme of “more than six flowers” was interpreted in one of two ways. There were six entries that had six or more plants and the other six entries had six or more flowers, predominately the flowers being on one inflorescence.

The competition was tight with Jane Higgs’ Caladenia tentaculata (syn. Arachnorchis tentaculata) winning by one vote. In South Australia it is known as the King Spider Orchid or Large Green Combed Spider and in Victoria is named the Eastern Mantis Orchid. As it is the largest of the Green Combed Spider Orchids, it is easily identified by its size. But there is variation and sometimes there are patches of small sized plants.

This happened to Rudie Kuiter on one of his orchid forays when he came across of patch of C. parva and small sized C. tentaculata growing together. In his book Orchid Pollinators of Victoria (page 29), he records how he distinguished the differences between the two species – “Except for some minor differences in the labellum they looked much the same. In C. tentaculata the upper margin teeth are longest, whilst in C. parva the central ones are longest. Labellum calli usually run into the red tip on C. parva and just short of the red in C. tentaculata, ...

Though I could not find these details recorded in any of the field guides I consulted, the differences were obvious when comparing the images of C. parva and C. tentaculata on the Retired Aussies website, www.retiredaussies.com

References:

Kuiter, R. H., Orchid Pollinators of Victoria, Fourth Edition. Aquatic Photographics

http://www.retiredaussies.com/ColinsHome%20Page/Orchidssa/Arachnorchis/Arachnorchis%20parva%20SA/Arachnorchis%20parva%20SA11.htm

http://www.retiredaussies.com/ColinsHome%20Page/Orchidssa/Arachnorchis/Arachnorchis%20tentaculata/Arachnorchis%20tentaculata%20King%20Spider%20Orchid.htm

2017 September Winning Picture

1709 sm JF Thelymitra x truncata

 

Natural hybrids are both fascinating and challenging. Fascinating because they don’t occur readily, (although of all the plant families, orchids have one of the greatest propensity for hybridising). Challenging because of the difficulty in determining the parents unlike the manmade hybrids where we can track which parents are being used to make the hybrid.

Obviously, the hybrid will share characteristics of both parents and this is the case of this month’s winning photograph, John Fennell’s Thelymitra x truncata. In the South Australian setting, a spotted orchid hybrid suggests that one of the parents will always be T. ixiodes/juncifolia and because it is blue it is most likely that the other parent will also be blue, from either the T. pauciflora or T. nuda complexes. This is true also for T. x merraniae. This is because there is no naturally occurring blue pigment. Whereas a pink or yellow parent and a blue parent will not produce a blue hybrid. Consider T. x chasmogama, T. x irregularis, T. x macmillanii are never blue.

Finally, it is fitting that this should be the winning photograph as this is the centenary month (September 2017) of its presentation to the Royal Society of South Australia, by Dr R S Rogers who also named this hybrid. The other hybrids entered were Jane Higgs Caladenia Harlequin and Diuris Earwig, both cultivated plants; Pauline Meyers Caladenia falcata X Drakonorchis barbarossa; John Fennell’s Caladenia x idiastes, T. x irregularis; Rickey Egels T. x macmillanii along with Lorraine Badger’s Caladenia roei hybrid and Caladenia x ericsoniae.

Reference

https://www.biodiversitylibrary.org/item/109628#page/353/mode/1up

https://nossa.org.au/2017/07/28/2017-june-winning-picture/

https://nossa.org.au/2014/09/26/thelymitra-x-irregularis-beautiful-but-only-a-hybrid/

Bates, R. J., ed. (2011). South Australian Native Orchids. Electronic version, 2011. NOSSA

Rules of entry:

The subject matter must have something to do with Australian orchids.  Any format is acceptable including Photo shopped images, artwork, etc

 

2017 August Cultural Notes

Steve Howard writes cultural notes for Adelaide conditions. These are his notes for August; for both epiphytes and terrestrials.

WATERING

Mounts daily.

Pots weekly. Small pots twice weekly depending on weather. Drier conditions for hot cold types. Terrestrial pots can dry out faster on warmer days so keep a watch on conditions.

FEEDING

Epiphytes: Recommending feeding towards months end as days lengthen. Many plants in strong spike growth and flowering now.

Terrestrials generally don’t need to be fed although weak organics like Seasol and Powerfeed applied in low doses can benefit colony type greenhoods.

PESTS AND DISEASES

Epiphytes: Botrytis will rot new buds in cold damp weather as fast as it attacks new growths from now. Aphids will increase sharply this month and favour new growth and spikes.  Pyrethrum sprays eco friendly and work well, so does a hose but dry spike straight after.

Some terrestrials will rot this month if conditions have been too wet or stagnant over winter. Note this for next season and add more drainage if this has been an issue.

 

GENERAL

Epiphytes: Keep flowering plants under cover  to enjoy. Soon will be the time to start thinking about re-potting and division as spring nears.

Keep flowering terrestrials out of strong winds and heavy rains as flower stems on some varieties are quite weak when grown in cultivation

Additional:

Later August will produce some warmer drying days as spring nears. Ensure small pots and plants don’t dry out at this time. Good time to check out seedling lists and prepare orders to ensure your plants arrive at the commencement of a new growing season.

den-alick-dockrill-paleface-jb-1

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2017 March Winning Picture

As part of 40th NOSSA anniversary, the theme for this month was Leptoceras menziesii (Hare Orchid or Rabbit Ears). Entries were received from John Badger, Pauline Meyers, Robert and Rosalie Lawrence, with John Badger’s being declared the winner.

1703 sm JB Leptoceras menziesii

In February 1978, it was announced that the nascent NOSSA society required an emblem. Members were invited to send in drawings, to be judged by members and then ratified by the committee. Mrs Chris Butler (Ron Robjohns’ daughter) was the winner. The first Leptoceras menziesii flowers to be benched at a NOSSA meeting were in September 1978. It appears to be an easy plant to grow but a most difficult one to flower.

This seems to be because it is fire dependent. In spring, it will flower profusely if there has been a summer fire such as occurred after the 2015 Sampson Flat (SA) fires. It is possible that the gas ethylene produced during a fire event may initiate the flowering response.

Otherwise, apart from the occasional flowering plant, it will be mainly leaves that are found when out in the field. The single leaf of this plant lying prostrate along the ground is distinctive. It is firm, boat-shaped, glabrous (no hairs), with a fine ‘snake-skin’ pattern. Interestingly, sterile plants can be mistaken for a plant with a developing bud as there will be at the leaf base a ligule (a thin membranous growth, often found on grass stems).

 

Reference

Backhouse, G, et al (2016) Bush Gems: A Guide to the Wild Orchids of Victoria Electronic version

Bates, R. J., ed. (2011). South Australian Native Orchids. Electronic version, 2011. NOSSA

Lawrence, R. W., (2011) Start With The Leaves

NOSSA Journal Volume 2 No 6 July 1978

NOSSA Journal Volume 2 No 9 October 1978