Learning the language of moss
Learning the language of...
Tortula ruralis
A species with requirements so different to sphagnum that they rarely meet.
Habitat
T. ruralis thrives in exposed, nutrient-poor environments: rocky outcrops, urban pavements, quarry spoil, and dry grasslands. It’s one of the few mosses that can handle full sun and long droughts, making it a pioneer in disturbed or degraded habitats. The specimen in the pictures was raised on a large, dry hummock above the wetter ground.
How to recognise
This moss forms low, dense cushions with short, upright shoots. When dry, the leaves twist tightly around the stem, giving it a wiry, reddish-brown appearance. After rain or dew, it rehydrates rapidly, turning a vivid green and unfurling its lance-shaped leaves. The leaf margins are recurved, and the midrib often extends beyond the leaf tip as a fine awn. It’s this ability to survive desiccation, known as poikilohydry, that makes Tortula ruralis so remarkable. It can shut down during drought and resume photosynthesis within minutes of rehydration.