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Pauridia scullyi [Cape Star]

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#1 nfoto

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Posted 17 November 2015 - 18:22

Rørslett, B. 2015. Pauridia scullyi Baker (Hypoxidaceae). African flowers photographed in visible and ultraviolet light. http://www.ultraviol...ully-cape-star/

Syn. Spiloxene scullyi (Baker) Garside

Found in the Kamiesberg area near Kamieskroon, Northern Cape, South Africa. September 2015. The plants were growing in shaded cracks in a rock face.

Attached Image: PAUR_SCU_G1509066567_VIS.jpg
Image reference: PAUR_SCU_G1509066567_VIS
Visible light: Nikon Df, Voigtländer 125 mm f/2.5 APO-Lanthar lens, daylight

Front view of flowers in UV shows the large UV-dark patches on the basal part of the sepals.

Attached Image: PAUR_SCU_I15089062784_UV.jpg
Image reference: PAUR_SCU_I1509062784_UV

However, the rear view demonstrates an entirely different UV appearance, in which there are no basal darkening. Instead, the lower sepals are rendered in a blue hue compared to the pale yellow of the upper circle of sepals.

Attached Image: PAUR_SCU_O1509062785_UV.jpg

Both UV images obtained with Nikon D3200, UV-Nikkor 105 mm f/4.5 lens, Baader U2" ('Venus') filter (built-in), SB-140 flash.

References:
http://www.ultraviol...-r%C3%B8rslett/

[ Published 18 November 2015]

#2 Andrea B.

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Posted 18 November 2015 - 03:11

And yet another UV surprise !
Very interesting.
Andrea G. Blum
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#3 nfoto

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Posted 18 November 2015 - 08:38

Indeed. The differentiated UV rendition was a surprise, but apparently a widespread feature. A lot of the African flowers I documented on this trip to Western Cape and Namaqualand had a similar duality in their UV signature. This was mainly seen with the members of Asteraceae, but might be a spurious correlation as my main efforts of documenting each side of the flower structure in UV concentrated there.

It has to be understood that the species diversity in this region is massively high by any standards and only the tiniest fraction of these species can be photographed by a single person on a single trip. I will not begin to elaborate on the challenge of assigning correct IDs to the sampled species. The occasional identification errors probably are unavoidable, but I tried to post several photos of each plant so as to enable better identification by those more familiar with the African flora than myself.

#4 Andrea B.

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Posted 18 November 2015 - 20:16

Identification is always subject to updates. Else we would never get anything posted. "-)
Andrea G. Blum
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#5 nfoto

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Posted 18 November 2015 - 21:06

You might misread me. What I intended was that the first posting is conducted with the ID found most plausible after checking details against all available information (from published prospectus, local floras, field guides, etc.) sans official herbaria. However, when one encounters a regional flora containing tens of thousands of species and the available literature is not up to the level of detail we are seeing say in European floras, the occasional errors should be expected.

#6 Andrea B.

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Posted 19 November 2015 - 00:52

No, I understand! We use the best flora/guides/keys/online references we can find. But every location has some uncertain areas. New species are still being discovered out west here, for example.

This summer I learned that there was a herbarium on Mount Desert Island where we go every summer. But I'm not good with dried, flattened specimens.
Andrea G. Blum
Often found hanging out with flowers & bees.