Australian Orchids: The How, Where, When & Why

It’s been a little while in coming, but here is the second of a three part educational video about Australian Orchids.

Orchids are special.

They are unique but even more they are important. Orchids are the barometer to the health of the ecosystem.

So, watch and enjoy the video …

To watch the first video click here.

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Thelymitra Column Features Part Two

This article is a completion of the Thelymitra Column article which appeared in the NOSSA Journal, Volume 42 No 8 September 2018. Click here for Part One.

The first part looked at the features and terms used by botanists to describe various parts of the column, a major identification feature of the sun orchids.

And as previously stated we cannot physically dissect an individual flower, but we can make use of photographs to spot the various features.

The diagram below is that of T. nuda (based on the taxonomy of 1984) column whilst the photographs are that of T. glaucophylla column (as T. glaucophylla is one of the T. nuda complex). The column of these two are similar.

 

What makes an Orchid and Orchid?

Orchid flowers are extremely variable in appearance, ranging from mimicking spiders, flying ducks, helmets, ants, etc. This variety also can cause some confusion. People have mistaken a different type of flower for an orchid and vis a versa.

This raises the question of what makes an orchid an orchid? With so much variety, how can they possibly belong to the same family?

Using orchids found in the Adelaide Hills, the following video shows three key features that helps identify a flower as an orchid. These three features are found in all orchids worldwide.

So watch and enjoy …

Waiting for the rain …

Last year we waited for the rain. The rain heralds the start of the orchid season. Last year the season was dry, very dry. It was below average and it was hot.

So how did the orchids fare in the Adelaide Hills? The start of the season was slow with our first field trip not being until May 26 because of the lack of rain.

At the time, the smallness of the plants was noticeable with one specimen of flowering Leporella fimbriata standing no more than 2 cms. Normally  the flower stem can be up to 25 cms tall. This trend of smaller plants continued throughout the year.

The following two photographs show the difference in size.

Small Leporella fimbriata

A miniscule Leporella fimbriata near an ant nest

Leporella fimbriata sm

And on January 28, we came across the smallest flowering Dipodium pardalinum that we’d ever seen. Normally, this genus can grow up to about 100 cms in height but this one barely reached above the height of Robert’s shoe, ie, about 10 cms. True this was an exception but overall there not many plants, and even they were spindly and small in comparisons with previous years.

Below are two photographs illustrating the size difference

Small Dipodium pardalinum

A very tiny Dipodium pardalinum

Dipodium roseum

An average sized Dipodium

So what is the outlook for orchids for 2019? That will depend upon the rains.

When does the orchid season get going? Again that depends upon the rain but expect to see the autumn orchids about six to eight weeks after a good rain episode.

So we wait for the rains ….

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

Clarification of Pterostylis valida

Short Paper 3 Identity of Pterostylis valida (Orchidaceae) by Rudie Kuiter was published in June 2017. In this paper, Rudie has tackled the difficult group of Rustyhoods or Oliogochaetochilus (specifically Pterostylis valida) within the genus Pterostylis. Many of the different species occur in isolated pockets over a wide geographical range. Differences can be subtle but Rudie has sought to clarify the distinction between P. valida  and similar species. Click here read the complete paper.

A typical flower at the type-locality, green with the usual stripes on the transparent parts of the hood, cup-shaped synsepalum and dark labellum swellings. Opposite page Image of the original 1941 description page by Nicholls of Pterostylis valida as a variety of P. squamata. It was cropped with the deletion of the description of Caladenia hastata, the other species. 

A typical flower at the type-locality, green with the usual stripes on the transparent parts of the hood, cup-shaped synsepalum and dark labellum swellings. (Image from Rudie Kuiter’s Short Paper)

 

Corybas Pollinators

Rudie Kuiter’s Short Paper 5, October 2017, is about he and his team’s observations on the pollination strategies of fungus-gnats with Corybas. A small section from the introduction is quoted below:

Certain flowers in large colonies were most popular over several days and both sexes were observed feeding on the boss, which suggests a food-related attraction. Virtually nothing was known about the Corybas pollinators and primary literature to date only offered hypotheses. Based on our findings, the persisting statement in literature that ‘Corybas species attract fungus-gnats as putative brood-sites’ is incorrect for the taxa in Victoria. No evidence of ovipositing in flowers was found. Females feeding looked gravid and were presumed to be unfertilised. All individuals looked fresh with undamaged wings and it was apparent they had recently hatched.

Is this a hypotheses that needs revising? Rudie definitely demonstrates the importance of careful and meticulous observations.

Click here to read the full article

Corysanthes diemenica 077

Corysanthes diemenica (Veined Helmet Orchid)

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

 

Orchids In Remnant Roadside Vegetation

This week’s post written by Leo Davis is an article (slightly edited) from The South Australian Naturalist 91 (1): 34 – 37 January – June 2017. In this article, Leo highlights the importance of  the role of roadside vegetation in preserving the native orchids and flora.

All photographs are by Leo Davis.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 OrcFig 1: Thelymitra antennifera hybrid

One of my rules of thumb is ‘If I am in a Conservation Park, I’m on ground that nobody could make a living from.’ One, usually more, of nutrient poor soils, excess salinity, extreme rockiness, steepness, poor moisture retention, low rainfall or even being waterlogged, will be a feature of the location. There are a few odd spots that have survived partly intact, that have good soil, sufficient rainfall, etc. These include cemeteries (The Nationally Critically Endangered ghost spider orchid (Caladenia (syn. Arachnorchis) intuta) holds on in a cemetery on Yorke Peninsula) or exclusion zones around water storages (including a reservoir reserve in Lobethal that the public can now access) or abandoned railway yards (including Sherlock, where so far I have found 21 species of orchids and part of a reserve in Halbury.)

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 2: Little Yellow Club Mallee Spider Orchid Caladenia (syn Arachnorchisverrucosa

When I go in search of plants with the Botany Group of the FNSSA (Field Naturalist Society of South Australia), or for orchids with NOSSA (Native Orchid Society of South Australia), or when I do surveys of threatened orchid species with DEWNR (Department Environment, Water and Natural Resources), or orchid seed collection with the Adelaide Botanic Gardens, or go on weeding parties to protect endangered species, the destination is always one of these deprived, rejected sites. The orchids I see are those adapted to or just hanging on in such sites. We never see orchids that lived on better soils, say on the Adelaide Plains. How many have become extinct?

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 3: Common Mallee Shell Orchid Pterostylis dolichochila

Wherever the land was suitable for agriculture it was clear felled. Almost nothing of the original flora and little of its associated fauna, were left. But there is a tiny flimsy exception. Crossing these highly productive agricultural zones are roads and sometimes these have remnant vegetation. For a person interested in orchids, these narrow strips are normally areas of slim pickings but occasionally finds are made. Near Halbury, the Nationally Endangered Halbury rufoushood (Pterostylis sp. Halbury or Oligochaetochilus lepidus) can be found in some roadside spots.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 4: Mallee Bearded Greenhood Pterostylis (syn Plumatichilos) sp. Mallee Bearded Greenhood

The most remarkable piece of roadside vegetation that I have come upon was discovered by and shown to me by Glenn Dean, the Environment Officer with the City of Murray Bridge. He found a section of predominantly broombush (Melaleuca uncinata) vegetation, only about 200 m. long, on the verges of a single car sandy track, east of Murray Bridge. It is so close to the vegetation that cars can be scratched. I have found 24 species of orchid (Glenn has found more) blooming there sometime between March and October each year. All images shown here (Figs 1–11) were made at this site. If the little used road was not there the land would have been under crop, being equal in quality to regularly cropped fields to either side, and is of much higher quality than any normally allocated to Conservation Park status. Most of the orchids found can indeed be found in some of the poor sites dedicated as Conservation Parks, including species similar to those found at Ferries McDonald and Monarto Conservation Parks with their poor sandy soils. But this spot, which for some reason supports species that do not grow just 100 metres east or west along the road, has such species as the Nationally Critically Endangered Mallee Leek Orchid (Prasophyllum constrictum) (Fig. 8), that requires soils as good as those demanded by wheat, so it is essentially doomed.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 5: Rusty Rufoushood Pterostylis biseta (syn Oligochaetochilus bisetus)

Its single plant sighting here is regarded as a ‘rediscovery’ of a species not seen for years. In the longer term I guess this tiny site of orchid species richness is in a transitory state and most species will disappear. The surrounding cropping land is neither a source of seed nor a suitable landing site for it and it provides damaging wind blown nutrients and other chemicals. So I will cherish it while it lasts and hope others appear, if only briefly. Here is a reminder, that most of you do not need, of the value of roadside vegetation (with the understanding that it can contribute to native animal mortality) and that we should manage, extend and guard its presence.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 6: Rufoushood Pterostylis (syn Oligochaetochilus) boormanii complex sp.

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 7: Cinnamon Donkey Orchid Diuris palustris

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 8: Mallee Leek Orchid Prasophyllum constrictum

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 9: Limestone Tiny Shell Orchid Pterostylis cycnocephala
(syn Hymenochilus calcicolus)

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig. 10: Caladenia (syn Jonesiopsis) capillata x Pheladenia deformis hybrid

Microsoft Word - SAN Vol. 91, No. 1, Jan-Jun 2017  pp. 34-37 Orc

Fig 11: Small Rustyhood Pterostylis pusilla (syn Oligochaetochilus pusillus)


Returning the Water

Each month the Native Orchid Society of South Australia has a special speaker. April’s speaker was Mark Bachmann from Glenelg Nature Trust. He spoke on the The Hydrological Restoration of Glenshera Swamp, Stipiturus Conservation Park.

At time of settlement swamps were common on the Fleurieu Peninsula but now they have almost all but disappeared. This has come about because of the clearing of land for farming beginning in the 1940s. There are now very few swamps left in the area. As a result in this region, the swamp orchids potentially face extinction.

BUT Mark’s talk was a good news story. In April, the Glenelg Nature Trust with the help of the Conservation Volunteers Australia (a Green Army program) began the work of reinstating the original creek by the judicious placing of regulating structures along the principal drain.

The good news is that the water returned as they were building the structures.

It was also a good news story because of the cooperation of different groups including a local land owner who was willing to have some of their land returned to swamp and no longer be available for their horses to graze.

We look forward to seeing the swamp refill and learning how the orchids respond.

Below are some of the orchids found at Stipiturus. Click on the images to go to the three articles documenting the work at Glenshera Swamp.

Thelymitra cyanea

Thelymitra cyanea

Cryptostylis subulata 008

Cryptostylis subulata (Moose Orchid)

Prasophyllum murfettii sm

Prasophyllum murfettii (Denzel’s Leek Orchid)