Study finds petal 'windows' change light and heat inside flowers, affecting microbes

Some flowers have petals with small semitranslucent sections — partly see-through areas — according to Phys.org. Research published in the journal New Phytologist reports that these "windows" alter the amount of light and heat entering the flower. That creates conditions influencing how many microbes live inside, the outlet reported on 7 October 2026.

Field experiments showed that petal windows transmitted more ultraviolet and infrared radiation — types of light people cannot see — than pigmented tissue, according to Phys.org. The report said internal floral temperature predicted microbial numbers. Warmer flowers harbored fewer microbes.

Jessica Williams, a Ph.D. student at Florida Atlantic University, is the study's corresponding author. "One of the exciting things about this work is that a seemingly small floral trait can change the physical environment inside a flower in ways that affect its microbial community," she said.

Phys.org reported that microbial communities living inside flowers can affect nectar quality. "Because floral microbes can influence nectar traits and plant-pollinator interactions, these results suggest that flower structure may have ecological consequences that extend beyond the flower itself," Williams said.

The study, "Petal infrared transmission warms flowers and reduces microbial abundance," was published in New Phytologist in 2026. Its DOI is 10.1111/nph.71608.