Cichorium intybus L. (Asteraceae). Common Chicory. Flowers photographed in visible and ultraviolet light, including simulated bee colours.

This is the wild form of the vegetable chicory. It is common along streets and paths.

Flowers were photographed near Bensheim, Germany 15 October 2012.

All images were taken with a broadband-modified Panasonic Lumix G1 and the EL-Nikkor 80mm/f5.6 at f8.


 
Visible light image with IR-neutralisation-filter ND (Optic Makario), ISO 100:

image reference: NCH_P1060273_120918


UV-image, Baader U-filter 2”, ISO 400, sunlight

image reference: NCH_P1060276_120918


“simulated bee-colours”: composite image of the greyscale converted UV image (-> blue) and the blue (-> green) and green (-> red) channel of the visible light image. The goal of this is to mimic the spectrum that bees and other insect-pollinators can see.
 
image reference: NCH_P1060275_RGB_sw_121015

 
Interestingly, the petals that appear blue with white centre parts in visible light are UV-dark in the center and get UV-brighter towards the tips. The filaments are also very UV-dark.
The simulated bee colours show a prominent bee-yellow centre that guides the pollinators.

Bryonia dioica Jacq. (Cucurbitaceae). White Bryony. Male and female flowers photographed in visible and ultraviolet light.

Bryonia dioica Jacq. (Cucurbitaceae). White Bryony. Male and female flowers photographed in visible and ultraviolet light.
Only few species of the family Curcurbitaceae are found in central Europe. B. dioica is probably the most common of them. As the Latin name indicates the plants have either only male or only female flowers. These are mostly pollinated by the bee Andrena florea that feeds only on Bryonia species. In the river Rhine valley, at least in the greater Frankfurt area, both species (bee and plant) are quite common. Female flowers are significantly smaller compared to the male flowers. The later berry is already visible.
 
Male flowers were photographed near Bensheim, Germany 8 May 2013.
Female flowers were photographed near Bensheim, Germany 13 May 2013.
 
All images were taken with a broadband-modified Panasonic Lumix G1 and the EL-Nikkor 80mm/f5.6 at f8-11.

Male flower: Visible light image with IR-neutralisation-filter ND (Optic Makario), ISO 100

image reference: NCH_P1090133_130608


Male flower: UV-image, Baader U-filter 2”, ISO 400, sunlight

image reference: NCH_P1090136_130608

Male flower: Visible light image with IR-neutralisation-filter ND (Optic Makario), ISO 100

image reference: NCH_P1090142_130608  

 Male flower: UV-image, Baader U-filter 2”, ISO 400, sunlight

image reference: NCH_P1090142_130608


 Female flower: Visible light image with IR-neutralisation-filter ND (Optic Makario), ISO 100

image reference: NCH_P1090265_130613

 
Female flower: UV-image, Baader U-filter 2”, ISO 400, sunlight

image reference: NCH_P1090262_130613
 
In both genders the petals are quite UV-reflective. The green veins and inner parts of the flowers are UV-dark.

European spindle (Euonymous europaeus): UV reflexion and UV-induced visible fluorescence.

So far, I have published only images that show the UV-reflexion of flowers. However, some flowers show also very interesting UV-induced visible fluorescence. The latter can be documented by illuminating the flowers with UV-light in the dark, or at least under dim light conditions. Photographing fluorescence does not require a modified camera, since visible light is captured. Using an appropriate light source and the setting the white-balance has a significant effect of the appearance of the photos. I will write about this in more detail later, after acquiring some more experience. For now, just an example.

First, the visible light image:

Second the UV-photo using the Baader U-filter. The sun was the only light source. The petals have a UV-reflecting base but are mainly UV dark towards the tips.

Third the flower illuminated with a LED-UV-torch with a peak output at 365 nm (photographed in the dark):

Even with some background illumination the UV-induces fluorescence is visible: