Wall-screw moss glistening with water droplets, Netherlands

© Arjan Troost/Minden Picture

Magnificent moss, magnified. Tortula moss, Netherlands

This elegant plant dappled with water droplets is actually a variety of moss: Tortula muralis, better known as wall-screw moss. It's found all over the world, even in urban areas where more sensitive mosses have a hard time thriving because of dry soil and air pollution. Mosses in general are accurate monitors of air pollution. They absorb air and water, so contaminants can be measured in their cells.

Wall-screw moss is just one of up to 25,000 species of moss, ancient plants that date back 450 million years. The hardy bunch have weathered …..