Raindrops Help Flowers Evolve

Scientists in China have discovered that the simple raindrop may be an important factor in the evolution of flowers.

In a study covering 80 species of flowers, scientists found that flowers have been evolving into different shapes and structures partially to stop their pollen from getting wet. Some flowers even evolved waterproof pollen to avoid the problem.

The findings go some of the way to explaining why many flowers in rainy areas have either droopy flowers, or close their petals. Charles Darwin is one of many researchers that have theorised that flowers may have evolved this way in order to protect themselves from damage by rain, and water diluting their nectar.

The scientists recorded how the flowers of various species responded to rainfall, monitoring whether the flower moved to protect the pollen, as well as determining how long pollen produced by each species remains viable in water.

What they found confirmed a strong link between rainfall and flower design, the researchers report in the New Phytologist.

“Some plants shelter their pollen grains through a change in floral orientation or closing their corolla on rainy days. For example, tulip flowers close their petals rapidly when rains come. We were surprised that some plants without pollen protection structures develop water resistant pollen. The finding of a high proportion of resistant pollen in no-protection species suggests that selection by rain contact favours pollen resistance to water.” Says Shuang-Quan Huang of Wuhan University in China

Source: BBC Earth News