March 2014 Winning Picture

03 PM Arachnorchis c

Taken at the same site as February’s winning photograph – Ramsay Conservation Park on Yorke Peninsula, the winning photograph was of an Arcahnorchis sp. by Pauline Meyers.

A positive identification was not possible due to a number of factors making firm identification difficult.  Most likely it is a hybrid of the Green-combed group of spider orchids and though not positively identified there are some things that can be observed.  The Green-combed group according to Gary Backhouse consists of three sub-groups, A dilatata (largest sub-group), A concinna and A integra, but David Jones has them as three separate gorups.

Some features of this group are

  • One of two flowers
  • Flowers mainly green or greenish and red
  • Labellum
    • Hinged and mobile
    • Maroon apex
    • Green comb-like teeth on the margins (edges)
  • Tepals (petals and sepals)
    • Green to greenish with red stripes
    • Brown to yellow clubs at the tips

From the photograph it can be seen that all the green-comb features are visible except for the clubs,  The dorsal sepal is obviously thickened but it is not as clear for the other two sepals.  This could be due to the angle of the photograph.

Another observation to note is that it is a freshly opened flower as suggested by the elongated appearance of the labellum.  As the flower ages the labellum curls further under itself.  It is important to remember that an old flower and a young flower of the same species could be mistaken as two different species.

In South Australia, species belonging to the green-comb groups are

  • A dilatata sub-group consisting of
    • A aurulenta, A clavula, A dilatata, A interanea, A macroclavia, A necrophylla,  A parva,
      A phaeoclavia, A septuosa, A stricta, A tensa, A tentaculata, A verrucosa, A villosissima
  • A concinna sub-group consisting of
    • A toxochila, A conferta
  • A integra sub-group consisting of none in South Australia

To iterate from last month – Orchids are an interesting group concerning identification.  Some are extremely easy to identify but others not so.

References:

Backhouse,  G.  (2011).  Spider-orchids  –    the  Genus Caladenia and its Relatives in Australia on CD Rom.
Jones, D. L. (2006). A Complete Guide to Native Orchids of  Australia  including  the  Island  Territories,  (2nd  ed.).  Frenchs Forest, N.S.W., Reed New Holland.
R.J.Bates.  (2011).  South  Australia’s  Native  Orchids (DVD) [Electronic Version]

Thank you to Thelma Bridle for reviewing the article.

 

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].

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.