Monday, October 15, 2012

Snake Orchids




Why would you burden a beautiful little flower that graces some of Victoria’s natural areas with sunshiney, lemony, spring-greeting flowers late in September or early in October, with the name “Snake Orchid”? 
   
This is what has happened to Diuris chryseopsis, also known by the much nicer name of “Golden Moths”. 



 I’ve wondered why the "Snake Orchid" appellation for years, and it only came to me this year, when I saw my first Golden Moths for the season, two days after I saw my first snake for the season.  

The rather pejorative name must be because Snake Orchids and snakes emerge at the same time.  Probably the very same week.   And I'm guessing  that whoever called them Snake Orchids – probably someone in a community of early settlers - realized that their arrival coincided with the emergence from winter hibernation of snakes in the same habitats.

Snake Orchids, or Golden Moths, are found in grassy woodland or open forest habitats, and are relatively common where intact understorey vegetation remains.  As, of course, are snakes.

The common name “Golden moths” does what common names often do – gives us something descriptive to call it. Its flower does have a moth-like delicacy and fragility (although in reality its quite a tough little plant).     Its Diuris-character “ears” look more like wings than ears.





“Snake orchid” is sort of a functional common name.   The orchid probably does nothing for snakes, but their arrival in the bush together tells us something.  You may never see a snake, but the appearance of the gorgeous pale lemon Golden Moths tells you that snakes are out and about too! The same factors, probably the slightly longer days and bit of warmth in the sun, probably trigger the emergence of both.





Diuris chryseopsis is widely distributed through Victoria and Tasmania.  It was until relatively recently called Diuris lanceolata, but was separated out from another Snake Orchid, an orchid endemic to a small part of Tasmania.   This endemic Tasmanian is Diuris lanceolata, common name Large Golden Moths, and is rare and endangered.    Diuris chryseopsis is not.

Confused?   So was I some years ago, especially when I was asked to undertake some survey work on a site where a previous report had stated that the site contained the rare and endangered Diuris lanceolata.   This, I realized was entirely inaccurate, but an understandable mistake, as some slightly older texts list Diuris chryseopsis as Diuris lanceolata.

 The facts are:

  •        Diuris lanceolata occurs only in a small corner of North-west Tasmania and flowers in summer.   It is listed both under the Commonwealth EPBC Act (1999), as Endangered, and under the Tasmanian Threatened Species Protection Act (1995) as endangered.
  •        Diuris chryseopsis occurs across Victoria and Tasmania, was once known as Diuris lanceolata but was separated out from it and assigned the new specific name of chryseopsis sometime during the 1990’s.   It is common and widespread, and flowers in spring – from September to November.   It has no threatened status.

Details can be found in the Tasmanian Government Threatened Species Listing Statement (found here http://www.dpiw.tas.gov.au/internnsf/Attachments/SROS-6VHVDC/$FILE/Diuris%20lanceolata%20listing%20statement.pdf)