The secret world of moss, ancient ancestor of all plants and vital for the health of the planet

Header image: Macromitrium microstomum is found throughout New Zealand on the trunks or branches of smooth-barked trees, or on rock. Silvia Pressel, Author provided

Katie Field, University of Sheffield and Silvia Pressel, Natural History Museum

When people consider extraordinary plants, most probably don’t spare a thought for moss. It blends in against the green background of plant life, and seems to grow everywhere – whether you want it to or not.

But this group of plants, which actually comprises between 12,000 and 15,000 species, is astonishing. Their almost unique resilience allows them to grow practically everywhere on Earth. They are helping scientists understand the evolution of life, and are one of the most ancient plant groups alive today.

A recent study by an Australian research team found that mosses are the lifeblood of habitats around the world, with plants and soil in better shape almost everywhere they grow.

Despite their importance, mosses are often overlooked due to their diminutive size. The smallest mosses, known as micromosses, measure only a few millimetres in length. Even the largest moss, Dawsonia superba, a species native to Australia, New Zealand and the Pacific Islands, only reaches heights of up to 50cm – a giant among mosses, yet still smaller than the average houseplant.

But in fact, mosses help hold up entire ecosystems.

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