Category: Monthly photo competition

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].

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.
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