Wahlenbergia stricta [Austral Bluebell]

[DaveO]

Oldfield, D. 2015. Wahlenbergia stricta (R. Br.) Sweet (Campanulaceae) Austral Bluebell. Flowers photographed in visible and ultraviolet light. http://www.ultravioletphotography.com/content/index.php/topic/1272-wahlenbergia-stricta-austral-bluebell/

 

Maldon, Victoria, Australia

7 March 2015

Australian Native Wildflower as Garden Specimen

 

Synonyms

 

Campanula gracilis var. stricta R. Br.

Campanula erecta Sweet

 

Comment

Wahlenbergia stricta is a dwarf tufted perennial herb which is widely distributed in eastern Australia in a range of soil types from sea level to alpine regions.

 

Visible Light: Pentax K-5 Full Spectrum Modification, Nikon Rayfact PF10545 MF-UV 105 mm f/4.5 lens, Metz 15 MS-1 flash, 1/180 s @ f/16 ISO 200, Baader UV/IR Cut Filter.

Image Reference: DO54356

 

Ultraviolet Light: Pentax K-5 Full Spectrum Modification, Nikon Rayfact PF10545 MF-UV 105 mm f/4.5 lens, Nissin Di866 Mark II flash, 1/180s @ f/16 ISO 200, Baader UV-Pass Filter.

Image Reference: DO54358

 

Ultraviolet Induced Visible Fluorescence: Pentax K-5 Full Spectrum Modification, Nikon Rayfact PF10545 MF-UV 105 mm f/4.5 lens with Baader UV/IR Cut Filter, Nichia NCSU033A UV-LED with Baader UV-Pass Filter, 30.0 s @ f/11 ISO 200.

Image Reference: DO54353

 

Reference:

Elliott, W.R. and Jones, D.L. Encyclopaedia of Australian Plants suitable for cultivation, Lothian 2010, Volume 9, p. 456.

 

Published 14 March 2015

[colinbm]

Beaut Dave

Col

[nfoto]

Interesting species, so superficially similar to the smaller taxa of European Campanula, such as C. patula. However, the UV signature apparently is different. Thus, the corolla of C. patula is highly UV reflective, in fact, to an extent that it is rendered almost perfectly "UV white".

 

An additional bonus you are able to show the fluorescence appearance of the flower as well. Much appreciated.

 

The only Wahlenbergia species familiar to me is W. albomarginata, seen on New Zealand some years ago. Alas, no UV record of it.

[DaveO]

What you don't see here is that the flower was on a VERY long, VERY thin stem which made the flower move with every little air movement, until I wrapped it in some of the other stems. I still had trouble getting a really sharp 30 second exposure, the images from this sensor seem to turn to mush at 400 ISO or above and I couldn't see much with shorter exposures. I suppose that the fluorescence of the pollen effectively sets the "white" point as I usually can't see much until I pull up the shadows in PN.

 

Trying to take the UV image of this in the field when I was using my Quartz lens and trying to focus a very dim image in LiveView was impossible.

[Andrea B.]

That is UV field work in a nutshell!

 

Sometimes I tuck a flower under the strap of a bag to hold it down while the breezes blow.

Take a small UV torch to aid in the focusing step, perhaps?

[DaveO]

It makes life so much easier with garden specimens that I can pick and take indoors. I wouldn't do that with this species as I think it's such a delicate flower that it would droop very rapidly, this one was in a small pot waiting to be planted. Methinks I will have to start a small farm of pots.

 

Dave

[nfoto]

A classic trick is using a clip attached to a short piece of flexible rod (metal wire striff enough to stand on its own when pushed into the topsoil). I bought a few industrial versions of this from wimberley.com (if memory serves) that had a holding spring-loaded clip on one end, a neat soft plastic thingie on the other, and an interconnecting pliable rod.

 

For focusing, a UV-capable camera with functional liveView in UV is a great bonus. If ambient UV levels are too low for focusing, throw a beam from a UV torch (Nichia etc.) onto th subject. Don't forget the UV-protecting goggles in the latter case.