English name: Black rock-moss
An acrocarpous moss that forms greenish brown to red-brown cushions or spreading patches that become blacker when dry. The nerve-less leaves are closely adpressed and, when moist, often point in one direction.
Capsules mature in spring and early summer.
In Scotland, Adreaea rupestris is widespread in upland regions where it grows on acidic to mildly base-rich rocks, including scree and walls. BBS distribution map
Look out for Diplophyllum albicans, Grimmia trichophylla, Racomitrium fasciculare and Racomitrium heterostichum nearby.
Confusion species: Andreaea rothii
scottishlichens.co.uk 