Hidden beneath the water’s surface is a botanical world that is among nature’s most innovative and ecologically important.

As I highlighted in a recent paper, an extraordinary range of adaptations have evolved in aquatic plants for life beneath the water’s surface. Some flower underwater, others capture animals in ingenious traps. Here are seven facts that show how these remarkable organisms challenge our assumptions about what plants are and how they survive.

Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories. This article is part of a series, Plant Curious, exploring scientific studies that challenge the way you view plantlife.

1. Plants can’t stop returning to water

When we think of plants, we often picture life on land: forests, grasslands and meadows. Yet throughout their evolutionary history, plants have repeatedly returned to the water, where they first evolved. Around 500 million years ago, plants moved from water onto land. Since then, many have moved back. Scientists estimate that the aquatic lifestyle has evolved independently more than 100 times across different plant groups.

Water lilies float their leaves on the surface, duckweeds drift freely and seagrasses live entirely submerged in the ocean. Some of these groups made their return over 100 million years ago. The repeated........

© The Conversation