Orchid Walks at Mt Lofty Botanic Gardens

For the last couple of years, NOSSA has been conducting spring tours at the Mt Lofty Botanic Gardens, South Australia, showcasing our beautiful native orchids to visitors far and wide.  They have come from not only Adelaide but from interstate as well as overseas from such countries as America, Germany, England and many others.  If you are planning to be in Adelaide during spring, then consider joining one of our walks, but for those who cannot attend here is a video for you.  So watch and enjoy …….

 

Orchids and Fire

Bushfires are a part of the Australian landscape.  The effect upon people and animals can be devastating but what of their effect upon orchids?  In 2012, Mike Duncan published a report Response of Orchids to Bushfire, Black Saturday 2009 for the Victorian Department of Sustainability and Environment.

Page one is a good summary of the effects experience by the orchids in Victoria:

This project addresses general community concerns about the response of orchids to the 2009 bushfires, by documenting the range of orchid responses encountered across all fire affected areas.  The information presented in the report is the result of data synthesis and direct field observations from a variety of sources, collected during the two years since the fires.
The response of orchids to the February 2009 bushfires was diverse, spanning the spectrum from being killed by fire, to being totally dependent upon the fire to flower.  In this report, the spectrum of responses that were encountered have been divided into five broad categories.

1. Fire Killed Species
Populations of epiphytes (e.g. Sarcochilus australis) and terrestrials with shallow tubers (e.g. Thynninorchis huntianus) were killed by the intense fire front.  In some cases, these species are likely to recolonise by seed from nearby unburnt areas, but in other cases, these species may require conservation intervention to assist in their recovery.

2. Fire Sensitive Species
Species such as Pterostylis alveata and Corunastylis despectans appear to have been sensitive to the bushfire, showing a large reduction in emergence over the following two years.  Populations of these species are likely to recover naturally over a number of years.

3. Fire Neutral Species
The response of the winter and spring flowering Pterostylis species were generally fire neutral, with their flowering rates neither increasing nor decreasing in the two years since the bushfire.

4. Fire Stimulated Species
The flowering of many Caladenia, Diuris, Prasophyllum and Thelymitra species was strongly stimulated by the 2009 bushfire, creating spectacular patches of massed flowering in the fire-blackened landscape.  Similarly, many smaller genera (e.g. Pheladenia and Glossodia) also showed a strong increase in flowering in response to the bushfire, sometimes producing clumps of more than 20 flowering plants.

5. Fire Dependent Species
There are four species (Burnettia cuneata, Pyrorchis nigricans, Leptoceras menziesii and Prasophyllum australe) that are dependent upon fire to flower.  These species are able to survive for extended periods without flowering.  Stimulated by the occurrence of the 2009 bushfire, these four species flowered en masse during spring 2009 (and to a lesser extent in spring 2010); the first time most of these plants have flowered since each site was last burnt.
Four nationally threatened orchid species (Caladenia concolor, C. orientalis, C. tessellata, and Pterostylis chlorogramma) occur within the area affected by the 2009 bushfire.  These species are part of an ongoing monitoring program, and the collected data offers an opportunity to quantify the post-fire flowering response of these species.  The data showed that grazing had negatively impacted seed production in each species since the 2009 bushfire.  It would also seem reasonable to assume that similarly high levels of grazing have occurred to other orchid species during this period.  A reduction in seed production is an important concern to any orchid species, but it is of particular concern to fire sensitive species, as it will lengthen the recovery time for these populations.  A reduction in seed production represents a lost opportunity for species that are fire stimulated or fire dependent, in terms of achieving recruitment to a population.  Fire-affected populations of these species will require careful management to ensure that seed production is not compromised into the future.

To see the full report, click here .………

2014 February Winning Picture

 02  85PM Arachnorchis brumalis x conferta

This month’s winner photographed by Pauline Meyers was a spider hybrid identified by Bob Bates as Arachnorchis brumalis x A conferta.

Orchids are an interesting group concerning identification.  Some are extremely easy to identify but others specifically the sun orchids, but also the spider orchids, can be difficult to identify partly due to the ease with which they are able to hybridise.

A frequent hybrid occurrence across Australia (see map for Arachnorchis distribution) is the pairing of the green comb spider orchids of the A dilatata complex with the white spider orchid of the A patersonii complex as seen in this picture.  A brumalis belongs to the A patersonii complex and A conferta to the green comb orchid.

Hybrids will be variable but obviously they will have characteristics of both parents.  By looking at the two parents it can be seen that this picture of Pauline’s contains features of both.  From the A conferta parent, the inherited features are the wide labellum of the green comb, thickened calli and the red on the segments whilst the long thin segments, glandular tips (osmophores) long and thin, not clubbed are from the A conferta.

I would like to thank Bob Bates for his helpful comments with writing this article and also Colin for his helpful website www.RetiredAussie.com with its many images of both A conferta and A brumalis which enabled me to view both species at the same time making it much easier to see the characteristics of both parents within the hybrid

ARACHNORCHIS Distribution Map sm

Reference for the map.

Australian Orchid Genera: an information and identification system
Electronic series: ABRS Identification Series
Publishers: Australian Biological Resources Study/CSIRO Publishing
Year: 2006
Authors: D.L.Jones, T.Hopley, S.M.Duffy, K.J.Richards, M.A.Clements, X.Zhang
ISBN-10: 0 643 09336 2
ISBN-13: 978 0 643 09336 2
Although originally from the disk quoted above, the map was accessed from this site
https://www.anbg.gov.au/cpbr/cd-keys/orchidkey/html/genera/ARACHNORCHIS_map.htm

Winning Picture for November 2013 Paracaleana Minor Section

The winner for Part two of November’s competition, Paracaleana minor (Little Duck Orchid) was David Manglesdorf.

In  South  Australia,  though  much  smaller  than  its  big brother  –  Caleana  major,  it  still  suffers  from  similar problems  ie  lack  of  pollinator,  vulnerable  status, extremely limited distribution within the Southern Lofty region.   The  Little  Duck  is widespread  in  the  east extending  from  Queensland  down  around  into  the South  East,  as  well  as  across  to  Tasmania,  plus  one other distant location.

One  of  the  differences  between  the  two  species  is that the minor  is  able  to  set  seeds  without  insect pollination occurring.  Could this possibly help provide an explanation for its other location?

There  is  one  colony  near  the  very  popular  tourist resort  of  Rotorua,  New  Zealand  where  it  is  called Sullivania minor,  (Paracaleana minor  is  recognised  as a synonym).  According to Graeme Jane it has been there ‘over a very long period’.  The speculation is that it  ‘could  have  arrived  during  one  of  those  periodic severe  bushfire  seasons  in  eastern  Australia  when
smoke, ash and apparently orchid seed and insects are carried high into the atmosphere and brought eastwards in  the  jet  stream  in  a  few  hours.   More  likely  though (since it has occurred nowhere else), it arrived in soil on the shoes of a visitor to the thermal wonderland.’

Just  some  food  for  thought  as  to  how  plants  may spread  around  the  world  –  but  it  still  doesn’t  take away  from  the  fact  that  it  is  also  another  one  that cannot  be  cultivated  and  needs  to  protected  where it naturally  grows  if  we  are  to  continue  to   enjoy  this species.

References:
Department Of Environment And Heritage. 2008.
Paracaleana minor: Small Duck-orchid.  Adelaide and Mount Lofty Ranges South Australia: Threatened Species Profile, May 2008.

Jane, G. 2006. Caladenia alata at Rainbow Mountain -Dispelling a Myth. [online]  Available at: http://www.nativeorchids.co.nz/Journals/98/page17.htm  [Accessed: 7 Feb 2014].

An Orchid You Can’t Buy or Grow

Question

I like the Flying Duck orchid.  It is truly a beautiful plant.  Where can I buy one?

Answer

The Flying Duck orchid or Caleana major is an unusual and unique flower.  Unfortunately, despite many attempts, no one has been able to cultivate it, so there is no supplier able to sell it.

It is a protected plant and it is illegal to remove it from the bush.  See the November Photo Competition 2013 for more details

November Photo Competition 2013 Part One

This month’s competition consisted of two sections – the Flying Duck and the Little Ducks.  The winner of the Flying Duck Orchid (Caleana major) picture was Patsy Love.  Bob Bates provided a commentary on the Duck Orchids in South Australia.

caleana majorCaleana major or Flying Duck orchid is unique and the unique shape of its flower was featured on an Australia Post stamp in 1986.  It is found only in Australia and it ranges as far north as the Tropic of Capricorn, around the eastern seaboard, across to the South Australian/Victorian border where there is a gap until the southern section of the Mt Lofty Ranges.  The latter distribution is know as disjunct because it is isolated from the main distribution group.  In the Mt Lofty region, the range has been severely restricted.  Records prior to 1983 show the distribution to be as far north as Cleland, Belair and Greenhill.  Post 1983 distribution consists of a few isolated locations in the south.  Though common in the eastern states, in South Australia it is listed as Vulnerable.
 The factors contributing to the South Australian vulnerable status is the restricted distribution as a result of loss of habitat due to clearing, grazing, weed infestation, inappropriate timing of slashing, etc.
Another factor is lack of pollinator.  Bob stated he has seen a male sawfly pollinating flowers (the labellum resembles a female sawfly) in New South Wales but no-one has ever seen it happening in South Australia.  He also added that non-one has ever seen a naturally occurring seed-pod.  It is suspected that the pollinators no longer live in South Australia.  Thus it is important that the plants and their habitats are not disturbed.
The survival of the duck orchids is made even more precarious by their popularity.  This seems to be the orchid that people most want to grow in cultivation.  Sadly some people attempt to remove them from their native habitat.  Tragically, when this does happen they inevitably die;  no one, not even experienced growers, have been able to grow them in cultivation.  It is important to concentrate on protecting its habitat if we are to continue to enjoy this unique species.
 References:
  • Calenana major, Adelaide Mount Lofty South Australia Threatened Species Profile, DEWNR, 2007
  • South Australia’s Native Orchids DVD 2011
  • Atlas of Living Australia http://bie.ala.org.au/species/Caleana+major Accessed 6th December 2013
11sm C major actual size
Enlarge or print this image to A4 size to see the actual size.
 
More information for this species and others are found in South Australia’s Native Orchids 2011.

Purchasing Orchids in Victor Harbor

Question

I missed the NOSSA Spring Show and I was wondering if there was a way of purchasing native orchids – Cym canaliculatum, non-hybrid Sarcochilus, Den falcorostrumD. ligguiforme & Bulbophyllums mainly, but also any others which will grow in shadehouse conditions in Victor Harbor?

Answer

There are several places where these orchids can be purchased.  Sizes vary so suggested you contact the growers.  Stick to larger and more established plants if you are a beginner.  Most will grow well in Victor with the milder climate.  If you get hold of Cym. canaliculatum make sure they are kept dry and under cover from April to October.

Orchids on Newbold, prop. Stephen Stebbing, can be accessed thru the net or better still, Ebay.  Only found Bulb. shepherdii on the net last night but I have seen exiguum (I got a piece) but in the way of species Dendrobium he has cucumerinum, pugioniforme, tertagonum, linguiformis, schoeninum, striolatum ( various clones of the species).  Has plenty of Sarcochilus but mostly hybrids, would suggest though he would have some of the typical species such as hartmanii, fitzgeraldii.  He does have the Cymbidium species such as suave and maddidum but doubtful  about canaliculatum.

Fernacres Nursery in Victoria deals will bush salvaged species from logging areas.  Mostly sold bare root but has good sized plants for reasonable prices.  This will be a better bet for picking up Den. falcorostrum and those mentioned above.  They may have cannaliculatum.

The Rock Lily Man (Gerry Walsh) I know was selling sizeable clumps of established bush salvaged falcorostrum recently and should still have a few left.  He has fabulous Den. speciosum available but be prepared to pay good dollars for show bench stuff.

Australian Orchid Nursery (Wayne Turville) specialises in natives but has moved a bit more towards Cymbidiums.  His mounted plants are first class and I know from time to time he has some of the other Bulbophyllums.

You can always ask them for other species.  They don’t always list everything and may have a piece or two of the lesser species lying around that they don’t list.

Most of these growers usually have links to other nurseries so with a bit of homework you can usually always get what you want.

Scale on Dendrobiums

Question:

I have scale on my Dendrobrium kingianum.  How do I to treat it?

Answer:

A dilute mixture of eco oil and water is safe to use on Dendrobriums. Use a mist spray bottle and follow up two weeks later with a second spray to kill the hatchlings.

Alternatively you can drench the plant with “confidor”, a systemic insecticide.

2011 POST FIRE SURVEY – MESSENT CONSERVATION PARK

Cathy Houston

Conducted by the Conservation group of the Native Orchid Society of South Australia Inc. for the Department of Environment and Natural Resources.

Members of the Native Orchid Society of South Australia and two volunteers conducted a three day orchid survey of Messent Conservation Park, following a prescribed burn that took place in March/April 2011.

The survey in burnt areas was undertaken from Friday 9th – Sunday 11th September, inclusive. A maximum of eleven people took part, not all being present for the entire survey time. Participants worked in pairs (or threes if numbers dictated such) and conducted ramble surveys within very rough grid areas of about 500 meters square. Because of the size of the burn area and access difficulty, none of the internal area was surveyed. However, many habitats were covered and extrapolation could predict what would be likely to occur in these areas. Some other vegetated areas were visited as well. These included flats covered in rushes, or sedges and rushes, a 16 month old prescribed burn area, a Pink gum (Eucalyptus fasciculosa) rise, mallee woodland and a Banksia herb-land.

Observations were taken of species present, numbers and any other detail of note, together with GPS location. A numbering code was used for most species.

The results were somewhat variable, presumably dependent on habitat types and their orchid population prior to the burn, the temperature of the burn and to a lesser extent, the emergence or otherwise of orchids prior to the time of burning. For instance, only one small population of Corunastylis (Genoplesium) was noted, this being a species that would have been flowering at the time of the burn. Similarly, no Eriochilus were observed in the survey area. However, Leporella fimbriata which emerges at a very similar time was present in some very large colonies.

The most abundant orchid by far was Pyrorchis nigricans. It was encountered in nearly all habitats of the survey area, the only exception being limestone ridges where it rarely appeared. Flowering had been promoted by the burn with perhaps about half the population in flower/going to flower. Density of the population fluctuated but it seemed to be consistently present. However, its absence was noteworthy from an area of burn undertaken in May 2010. The habitat was ideal for the species and given the proliferation throughout the 2011 burn one would have to speculate about the timing of that burn on that (and perhaps other) species. Very few species were located in that area at all. It has to be said in fairness though that the only Thelymitra epipactoides found in any burn area was seen in this 16 month old burn.

Perhaps the most orchid-rich habitat with regard to number of species was the limestone ridges. Some of the open flats had the least diversity. It was not easy to ascertain what the dominant vegetation had been in these areas. Conversely some of the flats had a good scattering of orchid species, the numbers of each being relatively low.

Winter flowering species were conspicuous by their low representation.  No Bunochilus (Pterostylis) were seen, few Urochilus (P.) sanguineus, Diplodium (P.) dolichochilum, Acianthus pusillus, Corysanthes (Corybas) species and Cyrtostylis robusta were seen in the burn area.  The only exception was Linguella (Pterostylis) sp. Mallee. It was encountered in small to medium sized colonies throughout the area, usually with a reasonable number of capsules developing. In a vegetated location Diplodium species was seen in good numbers.

Threats to orchids were minimal. Rabbits were present in noticeable numbers along the northern boundary. Similarly, there was some weed incursion along the northern boundary, Capeweed and one other being the main ones seen. Some predation was observed within the burn area, but nothing we would consider notable. Rabbit activity was also very evident in a flat/Pink gum rise on the track leading south to the boundary. Deer prints were observed throughout the areas we covered. A small flock of sheep encountered in the north eastern sector is of concern. They had free access to the park via a “kangaroo door” under the boundary fence, something they negotiated with ease when disturbed by a vehicle.

Species of significance were Thelymitra matthewsii and T. epipactoides, these both being nationally threatened species. Historical records existed for T. matthewsii from this park, but it had not been observed for decades, despite intensive searches having occurred following the 2002 burn. Some of this surveys records bear a similarity to historical records but since the latter were recorded prior to accurate global positioning systems it is uncertain about the actual locations. This species was encountered as mainly individual plants in about six different locations, usually in very low numbers. Some plants were just leaf but others were seed capsules. All but one group were located in burn areas, the species being very difficult to observe without the removal of much vegetation. It was noted that some of the area where the species was seen had been slashed. It was felt this could be beneficial to them. Observations in the lower South East seem to reflect this type of disturbance is beneficial to T. matthewsii and Thelymitra in general.

More than 60 plants of T. epipactoides were located in one area of a few hundred meters squared, with the exception of the aforementioned one plant in the 16 month old burn. Despite searching of hectares of similar sedge/rush-land, no others were located. Here again, it was thought that some random slashing of this habitat may benefit orchids that like the open areas, viz. Thelymitra, Diuris sp. Short tailed, Glossodia major, and some Caladenia species.
Present in low numbers on the limestone ridges was Arachnorchis (Caladenia) tensa, another nationally threatened species. Despite its national rating this species is more prolific in South Australia.

Another orchid that appeared in considerable numbers and most habitats was Arachnorchis (Caladenia) sp. South East. It grew as single or few plants right up to sizeable collections of plants, sometimes with up to about 50 in a group. Diuris sp. Short tailed was widespread and moderately common. Glossodia major was encountered as mainly single plants widely scattered. Caladenia carnea was in very high numbers under fairly dense mallee on the northern boundary. Microtis species when it was encountered, was in colonies with high numbers of plants. As a generalisation, Thelymitra were absent or in very low numbers. Exceptions to this were T. antennifera and T. benthamiana which were usually seen in very low numbers but widespread throughout the burn area. It was interesting to note that few of the latter were likely to flower, which contrasts with the 2002 burn when flowering was prolific.

One species promoted to flower by the burn was Prasophyllum elatum. It was widespread in most habitats, but not often in the flats. Plants varied tremendously in size and stature with some quite small plants flowering/going to flower. Predation of the leaves was relatively high, with nearly all being chewed down to between 100 to 150 mm. Buds were emerging from the open top of the leaf, instead of emerging from the side of an intact leaf. There were other Prasophyllum species present, but the survey was just too early to identify what these are likely to be. Most of these were found on the limestone ridges.

The orchid list held by NOSSA for Messent Conservation Park prior to this survey must have been somewhat limited because the number of species on our list has now been doubled. With the rediscovery of T. matthewsii in several locations within the park, the other two nationally threatened species present and the expanded knowledge of orchids within the Park we must consider this was a very successful survey. We thank DENR South East for making this survey possible.

Murray Mallee Midges Autumn 2011

R.J. Bates May 2011

The title of this article refers of course to mallee midge orchids of the genus Corunastylis which have been poorly understood.

Summer and autumn 2011 saw good rains across the Murray Mallee from Pinnaroo to Renmark and thus NOSSA members took the opportunity to study mallee midge orchids in flower in March and April.  The results are summarised here.

Corunastylis sp. Box Flat
Ngarkat Conservation Park
Photo: June Niejalke

Aims:

  1. To match species to habitat.
  2. To assess the distribution and population of each species.
  3. To take images of all species.

Midges were found all the way up to Chowilla sand hills, which are just north of the River Murray.  Almost every patch of mallee eucalypts seemed to have some Corunastylis species but an understanding of their ecology was needed to find the flowers.  Degraded or weedy mallee did not have any midge orchids, nor was hard clay, loose white sand, bare trampled soil or dense ground cover worth searching as midges are very small plants and easily crushed, covered up or sand blasted.

Flowering plants were found mostly in the leaf litter under mature mallee, often with associated patches of native pine or circles of Triodia sp. (porcupine grass).  Areas with extra water run off and disturbed soil along road corridors seemed to have produced localised population explosions.  A 4WD vehicle proved handy for reaching remote corners of larger parks like Billiat Conservation Park near Alawoona.

The most common species was the red and green flowered mallee midge Corunastylis tepperi while the similar but purplish Corunastylis sp. Intermediate came in second.  Next came the black midge orchid C. nigricans which seemed to have finished in early March and were found mostly in capsule.

Species of the Corunastylis rufa complex were mostly found in the southern fringes of the mallee.  Their classification is ambiguous seeing Australian orchid expert D.L. Jones says Corunastylis rufa is confined to NSW.  The un-named species of the complex seen included Corunastylis sp. Dark midge and Corunastylis sp. Narrow segments.

Corunastylis tepperi
Alawoona
Photo: Rob Bates

In any case, no fringed labellum species of any kind were observed, so all mallee midges belong to the C. nigricans and C. rufa complexes.

Tiny fruit flies of several species were seen working the flowers but we could not tell if each midge orchid attracted a different fly as the flies are too small to compare!  I suspected that specificity of pollinators is low as apparent hybrid midge orchids were noted.
Recognising the different mallee midge orchids:

  1. If the flowers are bright green and the labellum is rounded, deep purple or maroon then it will be C. tepperi, also known as C. fuscoviride.  The latter is a better name as it means bright dark and green.  C. tepperi has a narrow spike of many tiny flowers.  The finished flowers and capsules will take on a yellowish look.
  2. If the labellum is rounded and the flowers are mottled brown to wholly purple-brown, except for white or white striped petals, the species is C. sp. Intermediate.

DNA studies may be required to check the species limits of the many taxa found.
It is doubtful that such a good display will be found next autumn!

Many thanks to NOSSA members who sent me images of mallee midges recently, especially June Niejalke.

Unknown member of the Corunastylis rufa complex
Carcuma Conservation Park
Photo: June Niejalke
Corunastylis sp. Intermediate
Billiat Conservation Park
Photo: Rob Bates
Corunastylis sp. Narrow segments
Keith
Photo: June Niejalke
Corunastylis nigricans
Karte Conservation Park
Photo: June Niejalke
Corunastylis sp.
Monarto
Photo: June Niejalke
Corunastylis sp. Dark Midge
Ngarkat Conservation Park
Photo: June Niejalke
Corunastylis tepperi aka C. Fuscoviride
Pinnaroo
Photo: June Niejalke
Corunastylis sp. Intermediate
Lameroo
Photo: June Niejalke