Researchers have revealed minuscule features on the leaves of a common desert plant that allow it to collect water from moist air.
Syntrichia caninervis (pictured) is a small moss that lacks roots. To understand how it uses its leaves to capture moisture, Tadd Truscott of Utah State University in Logan and his co-workers altered the relative humidity in their lab and used high-speed cameras and electron microscopy to study the plant's response. They found that a hair-like structure called an awn at the tip of each leaf has grooves and barbs that collect and transport water. Nanogrooves about 200 nanometres wide allow water from humid air to nucleate on the awn's surface, and larger microgrooves collect bigger water droplets from fog.
Small barbs along the cone-shaped awn provide places for droplets to collect before being transported down the awn to the leaf.
Nature Plants http://dx.doi.org/10.1038/nplants.2016.76 (2016)