Tag: Arachnorchis patersonii

March 2018 Winning Photograph

1803 A4 sm JF Arachnorchis formosa

Four very different species were entered this month. Ricky Egel’s autumn flowering Coryunastylis fuscoviridis (see February Journal for name usage), Rosalie Lawrence’s winter flowering Diplodium bryophilum and John Fennell’s spring flowering Stegostyla cucullata and Arachnorchis formosa.

It was no surprise that John’s A. formosa (syn. Caladenia formosa) was the winning photograph. Words such as stunning, spectacular, wonderful and attractive are used in the description of this rare orchid and is reflected in its common names – Scarlet Spider Orchid, Elegant Red Spider Orchid, Elegant Spider Orchid and Blood-red Spider Orchid. It is truly a stunning red flower with its drooping petals and sepals (tepals).

A. formosa is part of the large patersonii alliance which is characterised by white to reddish flowers with (mainly) drooping tepals ending in long, slender (sometimes thickened) sparsely to densely glandular (hairy) tails, labellum with short to long marginal teeth. The features that separate A. formosa from others in the complex are the large (~60 mm across) deep red flowers with long (~80mm) tapering, drooping tepals. Similar species to A. formosa is the smaller once common but now extremely rare Caladenia ‘Fleurieu Peninsula’ In Victoria there are some other similar species.

A. formosa is confined mainly to the South East and into south western Victoria.

References:

Backhouse, G., (2011). Spider-orchids – the Genus Caladenia and its Relatives in Australia, Melbourne, Electronic version.

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

2016 October Winning Picture

 

Quite a few pictures were entered this month.

Ricky Egel’s Thelymitra x irregularis, 1610-re-sm-thelymitra-x-irregularis

Pauline Myer’s Caladenia falcata and Caladenia carinsiana; 1610-pm-sm-caladenia-falcata

1610-pm-sm-caladenia-cairnsiana

Margaret Lee’s Diuris orientis and Nemacianthus caudatus;

1610-ml-sm-diuris-orientis

1610-ml-sm-nemacianthus-caudatus

Judy Sara’s Arachnorchis tensa;

1610 JS A4 Arachnorchis tensa.jpg

Greg Sara’s Arachnorchis stricta which had an unusual green coloured flower;

1610-gs-sm-arachnorchis-stricta

and Helen Lawrence’s Arachnorchis argocalla.

1610-hl-sm-arachnorchis-argocalla

Helen’s picture of the nationally endangered A. argocalla was the outstanding winner.  Now known as the White Beauty Spider Orchid^, it was featured last year as a winner with Pauline Meyer’s June 2015 entry*.

This is one of our largest spider orchids. For size, beauty and delicacy it rivals the Western Australian Caladenia longicauda ssp. eminens (White Stark Spider Orchid) and A. venusta, syn. Caladenia venusta (Graceful Spider Orchid) from Victoria and the South East.

It shares many similarities with these two species in that they are reasonably good size white flowers with a stiffly hinged labellum that has long, thin teeth and the segments have threadlike tips without clubs.  It is separated both geographically and in the type of habitat from these two species. A. argocalla is a plant of the inland hills and valleys.

Though primarily a white flower and part of the A. patersonii complex, A. argocalla has red colouring in the labellum which according to Backhouse may possibly indicate genetic introgression (that is long term mixing of the gene pool) with either the A. reticulata or A. leptochila complexes. Certainly, the colour of the labellum was quite variable ranging from white through to a deep red.

^Previously known as Common White Spider Orchid because of its abundance but now only known to a limited number of locations.

*NOSSA Journal, July 2015

Reference:

Department of the Environment (2016). Caladenia argocalla in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Thu, 3 Nov 2016 16:31:39 +1100

Introgression https://en.wikipedia.org/wiki/Introgression Accessed 4 November 2016

Bates, R. J., ed. (2011). South Australian Native Orchids. Electronic version, 2011. NOSSA

Jones, David L (2006) A complete Guide to Native Orchids of Australia, Frenchs Forest, NSW: Reed New Holland

Backhouse, G (2011) Spider-orchids the Genus Caladenia and its Relatives in Australia

 

NB: November Competition will be judging the monthly winners from this year.