A picture is said to be worth a thousand words, so look at these Victorian wildflowers photographed in visible light and UV.
Hibbertia humifusa (rising star guinea flower)
Visible light (Left)
UV light (Right)
The insect in the UV shot, which was not present for the previously taken visible image, gives some idea of the size of the flower. The stamens, which are yellow in visible light, become dark grey or black in UV light. It seems likely that UV-absorbing pigments are expressed in the stamens and anthers of the flowers in order to protect the genetic material of the flowers from UV degradation. Pollinating insects, which can see in UV light, may then be able to orient themselves to visit those areas. The petals themselves show a pale cream false UV colour.
My wife, Sue, has been an enthusiastic grower of Australian native plants for many years. If I place a garden-grown flower in my studio and take visible and UV photographs using flash as I do in the field, then darken the room and illuminate the flower with a UV-LED (light-emitting diode), with peak emission at 365 nm, I can take a photograph of the UV-initiated visible fluorescence (UVIVFL) of the flower. The visible, UV and UVIVFL images become a complementary set to describe and investigate the floral structure.
Acacia longifolia (Sydney golden wattle)
Visible light (left) UV light (Right)
Acacia longifolia (Sydney golden wattle)
UVIVFL light (Left)
Eucalyptus camaldulensis (river red gum)
Visible light (Right)
Eucalyptus camaldulensis (river red gum)
UV light (left)
UVIVFL light (Right)
When I started attempting to take UV flower photographs about six years ago, I was guided by a wonderful website that answered all my questions. I was surprised to find that nobody else on that website was taking photos of Australian native flowers in UV light. You will now find my images in that forum.
Eucalyptus flowers resemble acacia in their UV signatures.
Greenhood orchids are attractive subjects.
Pterostylis obtusa (blunt-tongue greenhood)
Visible light (Left)
UV light (Right)
Pterostylis obtusa (blunt-tongue greenhood) UVIVFL light (Left)
Sun orchids put on a brilliant display.
Thelymitra nuda (plain sun orchid) visible light (Right)
Thelymitra nuda (plain sun orchid)
UV light (Left)
UVIVFL light (Right)
Who would have guessed that these images could be found by simply looking at the world in a different light?