English name: Wall screw-moss
A distinctive acrocarpous moss that grows in tufts or neat cushions. When moist, the leaves spread out, when dry, the leaves twist and curl. The leaf blade is tongue-shaped and a long, silvery nerve projects from the rounded leaf tip, making the moss look hoary grey when dry. Narrowly cylindrical capsules are held on a purple seta.
Capsules mature in spring, summer and autumn.
In Scotland, Tortula muralis is widespread on outcrops of base-rich rock and manmade substrata like mortared or base-rich walls and stone, concrete and rooftiles. BBS distribution map
Look out for Bryum capillare, Grimmia pulvinata and Schistidium crassipilum nearby.
scottishlichens.co.uk 