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
- 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 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.
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.
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
Reference for the map.
Australian Orchid Genera: an information and identification system
Electronic series: ABRS Identification Series
Publishers: Australian Biological Resources Study/CSIRO Publishing
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
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.
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].