Flower of bastard pennyroyal (Trichostema dichotomum) when ...

The image presents two photographs of flowers from the plant species Trichostema dichotomum, also known as bastard pennyroyal. The top photograph captures a flower under regular daylight conditions, while the bottom photograph displays the same flower illuminated by a 365 nm ultraviolet (UV-A) blacklight.

**Top Photograph: Daylight Conditions**

* **Flower Appearance:** The flower exhibits pale purple petals with green sepals and slender white stamens.
* **Background:** The background is blurred but appears to be a natural setting, possibly a field or meadow.

**Bottom Photograph: UV-A Blacklight Illumination**

* **Flower Appearance:** When exposed to the 365 nm UV-A blacklight, the flower undergoes a significant transformation. The petals turn bright pinkish-purple with blue stamens, creating a striking contrast against the dark background.
* **Background:** The background of this photograph is completely dark, allowing the fluorescent effect of the flower under UV light to stand out.

**Comparison and Observations**

* Under daylight conditions, the flower appears more subdued in color compared to its vibrant display under UV-A blacklight illumination.
* The use of a UV-A blacklight enhances the visible fluorescence of certain pigments within the plant, resulting in an altered appearance that is not apparent under regular lighting.

In summary, the image showcases the unique phenomenon of fluorescent effects in plants when exposed to specific wavelengths of light. The photographs demonstrate how Trichostema dichotomum's flowers respond differently to daylight and UV-A blacklight illumination, highlighting the importance of considering the source of light when observing plant characteristics. – AI vision