Orchid Blogs

Australian Orchids: Their Role in Human Lives

In July, NOSSA resumed face to face meetings but with an innovation. We introduced Zoom meeting as part of our face to face meeting. We are hoping that this will allow more members to become involve with the meetings.

Our first speaker, Greg Steenbeeke, spoke to the meeting from Sydney; and we had another member joining in from Victoria. Greg kindly allowed us to record his talk which is available for all to hear.

Australian Orchids: Their Role in Human Lives
Speaker: Greg Steenbeeke

Anyone wanting to join our General Meeting, please contact the treasurer via email – nossa.treasurer@gmail.com

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.

Photograph Competition & Benched Plants July 2020

Email your votes for both the competition and benched plants to Marg Paech, nossa.editor@gmail.com by 5 pm July 27 2020

1. Thelymitra jacksonii
2. Diuris magnifica
3. Thelymitra cyanapicta
4. Urochilus sanguineus (syn Pterostylis sanguinea
5. Diuris sp
6. Urochilus sanguineus (synonym Pterostylis sanguinea)
7. Pyrorchis nigricans
8. Arachnorchis leptochila (synonym Caladenia leptochila)
9. Prasophyllum australae
10 Paintings of Caleana major, Corybas diemenica and Diuris orientis

BENCHED PLANTS

A. Pterostylis robusta, Red Form
B. Pterostylis ‘Nodding Grace’
C. Pterostylis robusta
D. Pterostylis sanguinea
E. Acianthus pusillus

NOSSA: The Doco

Last year, UniSA second year media students were required to produce a short documentary about a local organised. Three of their students, Vanessa Rossi, Tayla Elliot and Emma Sullivan, chose to produce a video about the work of the Native Orchid Society of South Australia. And for this we thank them. It was interesting working with them and they learnt a few things about our bush gems – namely that they are not big and showy!

Some adjustment needed to be made to the original video, but it is now available for viewing

It’s Arrived, the Wild Orchid Watch App …

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.

Glossodia major

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.

Diplodium sp Adelaide Hills

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.

Orthoceras stricta

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.