Advice from the past – Start Watering

In 1984, G.J.Nieuwenhoven was the editor of the NOSSA Journal.  In February of that year he wrote the following:

Welcome back to NOSSA.

 After the holiday break we are all looking forward to the next meeting to talk about our favourite plants and renew friendships.

Several members have reported an early start to the terrestrial season with Pterostylis species, a couple of Diuris species popping up already.  For some of the eastern states Pterostylis of the cauline group this is normal, especially if you keep the pots cool during the summer (a cellar is ideal but underneath a shaded bench in the shadehouse will do nicely). Very light watering should take place when the first shoots appear but do not overdo the watering or place pots in the sun for we are sure to get some more hot weather yet and this could cook your plants before you know it.

The Diuris are really out of season but it was probably the rain in late December and early January that started them off, anyway, these too should be kept slightly damp if they are up.

If you have not finished repotting by now it would be best to leave it until next year as the new shoots which are already beginning to grow from the tubers are very easily broken off while sifting them from the soil.

Apart from that all you can do is wait for the rains to come in March and then start searching for plants to appear – and keep those fingers out of the pots or you may damage one of your best plants looking for the new growths.

This is also the time to start taking notes when plants first appear, etc.:

  • when they flower and how many flowers from a given number of tubers;
  • what kind of soil; what conditions (i.e. shaded or not, damp or dry).
  • Anything that may assist in years to come to help you understand and grow our orchids better and, more importantly, multiply them.
  • A card index system would be a good way to store information, otherwise an exercise book will do.

                                                            Editor

The timing of the article tallies with the advice that was recently given at the end of February – start watering the terrestrials now if you haven’t already begun.  Hopefully by the flowering time you will have a lovely display of terrestrials such as the Thelymitra, Arachnorchis and Caladenia featured below.

 

Pot of Thelymitra Kay Nesbitt Cultivar copyPot of Arachnorchis argocallaPot of Caladenia latifolia cultivated by Les Nesbitt

Three Key Starting Points for Successfully Growing Australian Orchids

There is a lot of information on growing orchids so much so that it can become overwhelming.  As a novice, I’ve put together my observations which can be summed up in three key points.

One – Find a Mentor

The best and first thing to do is to join a local orchid club, such as the Native Orchid Society of South Australia (NOSSA), and find a mentor within the group.  There are many books but nothing substitutes for that personal interaction with an experienced grower who will know both the plant and the adaptions needed for the local conditions.  At the monthly meetings, NOSSA has a Grower’s forum where various aspects of growing orchids are discussed and questions answered.  It is well worth attending.

Two – Have an Equipment Kit

There are some things that are essential and it is good to have a basic kit to get started.  Later, more equipment can be added as one’s skill develops in growing orchids.  The necessary items would include:

  • Secateurs
  • Labels – these can be proper plant labels from a garden store or wooden lollipop sticks, so long as they are waterproof.
  • Pen – indelible ink pen or pencil (there are pencils that can write on plastic) as it is pointless having a labelled plant with the details washed off.
    • it may be necessary to use both current name and synonyms on the label eg Corybas/Corysanthes
  • Wettable Sulphur – necessary for guarding against diseases and is available from garden centres but Tomato Dust can be a good substitute although it is half the strength.
  • Sterilizing equipment
    • Good nursery hygiene techniques are important
    • Dilute bleach, tri-sodium phosphate (and possibly a small blow torch for metal tools)
    • newspaper
      • a different sheet for each orchid when dividing will help prevent transference of any disease, etc (don’t forget handwashing)
  • For Epiphytes
    • Ties and Stakes
  • For Terrestrials
    • Sieve for recovering tubers
    • Sheoak or pine needles for putting on top of the pots to stop soil and fungi splashing up on the undersize of the leaves
  • Pots – do not need to be fancy but the pot size will depend upon the species
    • Diuris prefer deeper pots; Corysanthes prefer wider, shallower pots whilst Pterostylis doesn’t seem to mind either

Three – Work within the Plant’s Growing Condition

This will require time, research, experiment and going back to the experienced growers.  Each one of us eventually needs to find what is the best setup for our individual location but some general guidelines would be:

  • Start with plants that are suitable for your current climatic conditions.  Obviously putting a tropical Dendrobium bigibbum under the patio in temperate Adelaide is not going to be successful.  For the terrestrials it is better to start with Pterostylis curta or a Microtis than a fungi dependent Arachnorchis tentaculata.
  • Research the plant you want to grow and then create the micro-climate necessary for the flourishing of the plant.  This will entail separating the orchids, don’t put shade lovers such as Corysanthes with those requiring brighter light eg the Thelymitra genus.
Dendrobium speciosum
Potted Epiphyte – Dendrobium speciosum
Thelymitra plants in pots
Potted Terrestrials – Thelymitra (Sun Orchids)

2014 November Photograph Competition Part 2

Part Two of the November competition consisted of photographs of insects on orchids. There was quite a range of insects but the winner was a draw between Cyrtostylis robusta (Winter Gnat Orchid) with an ant and Pterostylis curta (Blunt Greenhood) with a midge fly; both taken by Doug Castle.

With today’s technology it is not only easier to take crisp images but fine details can be seen particularly when enlarging the image. Hence when the pictures are enlarged it is possible to see hairs on the ant and feathered antennae on the midge fly.

With identifying orchids, it is often the detail that is important. Both of these orchids are distinctive and can be readily identified but it is good to examine why this is the case.

Pterostylis curta (Blunt Greenhood)
Pterostylis curta (Blunt Greenhood)

With the greenhood, there is enough detail to see that the dorsal sepal and lateral petals have united to form a galea, ie hood, and that the lateral sepals are semi-fused and erect resulting in lateral orifices (side gap) between the two structures. These are some of the features that separate Pterostylis* from the other greenhoods such as Diplodium, Speculantha and Taurantha. This becomes apparent when browsing through the greenhood photographs, pages 286 to 339, in Jones “A Complete Guide to Native Orchids of Australia”. Having established that the plant is a Pterostylis, the twisted labellum is diagnostic of a P. curta as it is the only one that is described with a twisted labellum. Although not all the identifying features are present, enough information is available in this picture for identification.

In contrast the photograph of the Cyrtostylis robusta only has sufficient data to confidently identify it as a Cyrtostylis species, having a distinctive labellum that is larger than the lateral sepals and petals. In South Australia there are only two species and according to Bates (2011), the distinguishing features between the two

Cyrtostylis robusta (Winter Gnat Orchid)
Cyrtostylis robusta (Winter Gnat Orchid)

appear to be the leaf, the bud and the labellum. In this picture, the angle of the image does not give a clear view of the labellum (it could possibly be damaged) and of course there is no bud or leaf. It is possible that the pale edges of the dorsal sepal may give a clue to species identification as C. reniformis has mainly darker buds than C. robusta. Obviously Doug was able to identify it from his observations of the other features not present in this photograph.

In summary, one image is not always sufficient for identification. As was discussed on the night, to confirm identification, orchids should always be photographed from more than one angle, including pictures of other parts of the plant.

*In South Australia, Pterostylis foliata is a possible exception as it has no obvious lateral orifice.

References

Jones, D.L., T. Hopley, S.M. Duffy, K.J. Richards, M.A. Clements & X. Zhang (2006) Australian orchid genera. An information and identification system. CSIRO Publishing: Collingwood, Vic.

Bates, R.J. (2011) South Australia’s Native Orchids. DVD-ROM. Native Orchid Society of South Australia Inc.: Adelaide.

Jones, D.L. (2006) A complete guide to native orchids of Australia, including the island territories. New Holland Publishers: Sydney.

NOSSA and the Lofty Block Threatened Orchid Recovery Project

In the NOSSA Constitution (2007) the aims of NOSSA “are to promote and engage in activities for the promotion and furtherance of :
  1. the culture, propagation, conservation, knowledge and scientific study of the native orchids of southern Australia and the Australasian region;
  2. the preservation of orchids as a species and their preservation within their native habitat.”

The article following is about one of the ongoing conservation activities with which NOSSA members were and are currently involved.  Quoted verbatim from SA Veg on the Edge, Vol 7, No. 1, 2007

Recovery Plan for 12 Threatened Orchids in the Lofty Block Region released
Since 1998, the Lofty Block Threatened Orchid Recovery Project (LBTORP) has been implementing recovery actions for threatened orchids in the Lofty Block region of SA. In late 2006, a draft recovery plan was completed for the following twelve species:
  • Caladenia argocalla (White Beauty Spider-orchid) – ENDANGERED (EPBC Act)
  • C. behrii (Pink-lipped Spider-orchid) – ENDANGERED (EPBC Act)
  • C. gladiolata (Bayonet Spider-orchid) – ENDANGERED (EPBC Act)
  • C. sp. ‘Brentwood’ (Ghost Spider-orchid) – Nominated as CRITICALLY ENDANGERED (EPBC Act)
  • C. macroclavia (Large-club Spider-orchid) – ENDANGERED (EPBC Act)
  • C. rigida (White Spider-orchid) – EPBC Act – ENDANGERED (EPBC Act)
  • C. woolcockiorum (Woolcock’s Spider-orchid) – VULNERABLE (EPBC Act)
  • C. xantholeuca (Flinders Ranges Spider-orchid) – ENDANGERED (EPBC Act)
  • Pterostylis bryophila (Hindmarsh Valley Greenhood) – CRITICALLY ENDANGERED (EPBC Act)
  • P. cucullata (Leafy Greenhood) – VULNERABLE (EPBC Act)
  • P. despectans (Lowly Greenhood) – ENDANGERED  (EPBC Act)
  • P. sp. ‘Halbury’ (Halbury Greenhood) – ENDANGERED (EPBC Act)
The recovery plan describes each of these twelve species in detail including their morphology, distribution, population size, habitat, and ecology.  Importantly, it also outlines the threats to each species and prescribes recovery objectives, targets, and actions for the next five years.
  • Determine population size and trends
  • Determine current extent of occurrence and number of sub-populations
  • Mitigate threats to sub-populations.
Recovery actions will be implemented for each of the twelve species in accordance with the recovery plan over the next five years by the LBTORP.  Community involvement is recognised as a key factor in the successful delivery of on-ground recovery actions.
Fact sheets and a webpage that provide up to date information on the program were recently completed … Joe Quarmby, Lofty Block Threatened Orchid Recovery Project Officer , SA DEH
(NB Joe Quramby now is the Threatened Flora Ecologist Natural Resources, Adelaide & Mount Lofty Ranges Partnerships and Stewardship and DEH is now Department of Environment, Water and Natural Resources, 2014)

The article may be seven years old but it is a good overview of some of the conservation work that NOSSA members have done with Joe Quarmby.

The full 176 page report can be found here.

 

Arachnorchis behrii (Pink Lipped Spider Orchid)
Arachnorchis behrii (Pink Lipped Spider Orchid)

 

Australian Orchids & the Doctors they Commemorate Part 8 of 20

Edwin Daintrey (1814-1887)

A medical student who abandoned his medical career just before graduation; he emigrated to Sydney, where he practised as a solicitor, cofounded the Linnean Society of New South Wales, and was appointed honorary secretary of the Australian Library in Bent Street.

Orchid species: Pterostylis daintreana

The Great Orchid Pretender

Actually there is more than one.

Frequently NOSSA receives a request to identify an orchid in someone’s garden.  Often, instead of an orchid (but occasionally there are orchids), it is the Ariasrum vulgare (common name Friar’s Cowl Lily or Cobra Lily).

Native to Asia and Europe, notably the Mediterranean and introduced to Australia, it is often mistaken for one of the flowers of the Pterostylis (Greenhood Orchids) or Diplodium (Shell Orchids).  Some have called it a Blackhood orchid others Snake Orchid.  It’s resemblance to the Greenhoods and Shell Orchids is superficial as they have none of the orchid features.  The dark purple hooded part is not the flower; it is a spathe (bract).  The flowers are minute hidden on deep down on the “tongue”.

The hood of the orchids is the combination of a deeply concave dorsal sepal interlocking with the lateral petals; and the fusing of the two lateral sepals.  Tucked away within the hood is the labellum (a modified petal) and the column (the reproductive organs of the flower).  The leaves of Ariasrum are quite large and distinctly different from any of the Greenhood orchids.

Friar's Cowl Lily 93RL
Arisarum vulgare amidst its large leaves
Pterostylis pedunculata 92RL
Pterostylis pedunculata (Maroonhood Orchid)
Diplodium robustum 92RL
Back view of a Diplodium robustum showing the dorsal sepal and two lateral petals that make up the hood of the flower

 

 

 

 

 

 

 

 

 

Diplodium robustum labellum and column 96HL
Looking into the Diplodium robustum – the labellum is the brown tip just visible at the front of the flower and the column is the brown white and yellow structure at the back
Pterostylis curta Labellum and column 92RL
Peering into the hood of a Pterostylis curta, the labellum is toward the front and the white and yellow structure to the back is the column
Friar's Cowl Lily open bract 93RL
The bract of the Arisarum vulgare has been split open to reveal the knobs which are the flowers. The flowers are so small a hand lens or microscope is needed to see them.

 

 

 

Australian Orchids & the Doctors they Commemorate Part 14 of 20

Richard Sanders Rogers (1862 – 1942)

An Adelaide physician, doctor-soldier and forensic pathologist who described 82 new orchid species (66 from Australia).

Orchids

Diplodium rogersii (= Pterostylis rogersii) or Curled Tongue Shell Orchid

Prasophyllum rogersii or Marsh Leek Orchid