Nettles in Color

What am I looking at?

This image shows a white nettle flower exposed to ultraviolet (UV) light and captured with a specialized camera filter. When different chemicals are exposed to UV light, they give off different colors due to each chemical’s unique structure. Therefore, the range of colors you see in this flower is the result of the different chemicals in the various parts of the flower.

Biology in the background

As a flower grows, the variety and concentration of the chemicals in its cells and surrounding tissues change over time. The chemical makeup of flower tissues also differs from that of the leaves and stems around them. Therefore, if scientists visualize the chemical makeup of a flower by placing it under UV light, it becomes evident that young buds (1) exhibit different colors than mature flowers (2), and that each of these exhibits different colors than the surrounding leaves and stems (3).

White nettle flowers can grow to about 3 centimeters across, or roughly 1.5 times the width of a human thumbnail.

Technique

These images were taken using a photography technique called ultraviolet-induced visible fluorescence.