March 2016 Winning Photograph

1603 sm JS Arachnorchis sp

We frequently receive entries from Western Australia but this month our entries were from both the west and the east. Allen Jennings entered a Calanthe triplicata (Christmas Orchid) from New South Wales. Pauline Meyer’s was from the west, (Western) Flying Duck Orchid, Paracaleana nigrita. The other entries were South Australian, Jenny Pauley’s recently photographed Leporella fimbriata (Fringed Hare Orchid), Greg Sara’s Thelymitra rubra (Common Pink Sun Orchid) and Judy Sara’s Plumatochilos sp. (Bearded Orchid) and Arachnorchis sp. (Spider Orchid).

The winning photograph was Judy’s Spider Orchid. Obviously it was one of the Green Comb Spider Orchids – A. dilatata complex. Of this group there are about a dozen possibilities. Knowing the location, Mt Boothby, helped to narrow the options with the most likely candidate being Arachnorchis stricta but it wasn’t convincing. It would appear that the tips of the sepals may have been chewed off when in bud.

A distinguishing feature of this species is that there are no clubs or osmophores on the sepals. Other species of this complex have clubs. Another feature is that the dorsal sepal is bent over the column unlike many other green combs which have an erect dorsal sepal. The features that caused doubt were lateral sepals looking droopy instead of being characteristically stiffly held out but dry conditions could cause this. The other was that the labellum did not strictly fit the description of A. stricta but then again it is a variable species.

The conclusion was a possible hybrid but there is no information on the likely parents or that is an atypical A. stricta that may have been damaged in bud.

This is an example of the difficulties that can occur when attempting to identify a plant from one photograph.

Reference:

Personal communications Thelma Bridle (NOSSA Conservation Officer)

Personal communications Bob Bates

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

Rules of entry:

The subject matter must have something to do with Australian orchids.  Any format is acceptable including Photo shopped images, artwork, etc

How to enter:

Email nossa.enquiries@gmail.com – jpg as large as you are able to send it, preferably A4 ratio for printing

Post: PO Box 565, Unley, 5061

Bring in to the meeting

Does South Australia Have a Christmas Orchid?

Western Australia has the Christmas Spider Orchid (Caladenia serotina) and the Christmas Leek Orchid (Prasophyllum brownie) whilst in the rainforest of the eastern seaboard is the Christmas Orchid (Calanthe triplicata).

In the disc South Australia’s Native Orchids, 2011, no orchid has the common name of Christmas Orchid but there are several listed that could be a possible candidate.  The ones that springs to mind are from the genus Dipodium.  In South Australia, there are four species flowering at this time:

  • D. campanulatum (Bell Hyacinth Orchid)
  • D. punctatum (Dark Spotted Hyacinth Orchid),
  •  D. roseum (Common Hyacinth Orchid)

    Dipodium roseum
    Dipodium roseum
  • D. pardalinum (Small Spotted Hyacinth Orchid)

    D pardalium Flower and Bud
    Dipodium pardalinum – Note the yellow staining on the bud and no stripes on the labellum

All four are in flower now – D. campanulatum and D. punctatum in the South East and D. roseum and D. pardalinum in the Southern Lofty Ranges.

There have been other orchids which would have flowered over the Christmas period but in recent days we are have been having an increasing number of dry year, especially this year (2015) which has resulted in the orchids flowering earlier.  For example, Prasophyllum murfetii

Prasophyllum murfettii sm
Prasophyllum murfettii (Denzel’s Leek Orchid)

finished flowering in November instead of December and Thelymitra circumsepta

Thelymitra circumsepta
Thelymitra circumsepta (Naked Sun Orchid). This photograph was taken on the 28th December 2010

finished flowering in early December but has been seen in flower soon after Christmas Day.

So does South Australia have a Christmas Orchid?  Until 1991, D. roseum was included under D. punctatum and the common name according to Bates and Weber 1990 was Christmas Orchid.  It seems a pity that when the split was made that neither species retained the common name but nevertheless as they both flower at Christmas, we do have a Christmas Orchid or two!

Reference:

Bates R J, Ed, 2011 South Australia’s Native Orchids, NOSSA

Bates R J & Weber J Z, 1990 Orchids of South Australia