• Ultraviolet Photography

UV-reflective molds on Clematis

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#1 enricosavazzi


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Posted 13 August 2014 - 10:27

The Clematis on the South-facing corner of my house is infested with UV-reflecting molds every year, starting from mid- to late summer. These are pictures of (probably) the very last flower for this year. The molds are visible even in the VIS range at this point, but not as well as in the UV. Typically they become visible in UV images (mostly between 340 and 390 nm, not so much at shorter wavelengths) long before they can be seen in visible light.

Converted Panasonic G3, CoastalOpt 60 mm, Bowens 1500Pro with uncoated tube and dome.

Attached Image: P1020421s.JPG
Baader UVIR Cut

Attached Image: P1020428s.JPG
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#2 JCDowdy


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Posted 13 August 2014 - 13:49

Oh my, that fungus has really infested your flowers!

Have you checked to see if this fungus is fluorescent?

#3 Andrea B.

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Posted 13 August 2014 - 14:58

Interesting captures, Enrico. And interesting that the fungus shows up well in UV also.

It is probably mildew caused by too much humidity? I've got some plants which get mildew attacks towards the end of every long humid New Jersey summer.
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#4 enricosavazzi


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Posted 13 August 2014 - 17:20

It may have something to do with humidity and rains. It does not seem to be fluorescent with a UV LED torch, but I have not tested properly. A curiosity is that it does not seem to be present at the back of the petals or on the leaves, it only likes to grow at the front of the petals.

I seem to remember reading about toxic molds strongly absorbing in the UV and fluorescing in the visible, and I have seen strongly UV-absorbing pathogenic fungi on tree leaves, but this one is instead UV-reflective.
-- Enrico Savazzi