Sumpweed (Iva annua) when exposed to regular daylight as ...

The image presents a comparative view of Sumpweed (Iva annua), showcasing its appearance under regular daylight and when illuminated by a 365 nm ultraviolet (UV-A) blacklight.

**Image Composition**

* The left side of the image features a photograph of Sumpweed in natural light.
   + The plant's green coloration is evident, with thin stems and leaves that appear similar to those of other plants.
   + The background is dark, which helps to highlight the plant's details.
* On the right side of the image, the same plant is illuminated by a 365 nm UV-A blacklight from Lick Creek Park. College Station, Texas, September 11, 2024.

**Key Features**

* Under UV-A light:
   + The plant's leaves and stems exhibit a purple hue.
   + This phenomenon is known as fluorescence, where certain materials absorb energy from the UV light and emit it back at longer wavelengths.
   + The intensity of the purple coloration varies across different parts of the plant.

**Conclusion**

The image effectively demonstrates how Sumpweed exhibits fluorescence under UV-A light, highlighting its unique characteristics. – AI vision