Anomalous Bristle-moss

Quite an easy species to spot once you've got your eye in. Growing on concrete, which is already a big clue. From the wonderful British Bryological Society website:
"O. anomalum differs from most British members of the genus in growing on rocks or masonry [especially concrete] rather than trees. The dark reddish-brown ripe capsules of O. anomalum are held well above low cushions of straight-leaved, green or brown shoots on a 2–4 mm long seta: a distinctive appearance not shared by other common mosses of the lowlands, except Ulota species that grow on trees and shrubs. Each capsule has 16 erect outer peristome teeth and strong ribs when it is dry. Mature capsules are reddish-brown, but light green when unripe. The calyptra is light brown and is sparsely hairy. Shoots are typically about 1.5 cm tall, with leaves 2.5–4 mm long, and capsules about 2 mm long."

Anomalous Bristle-moss, Orthotrichum anomalum. 

Sony ILCE-6000
Canon MP-E 65mm F2.8 G SSM
f8 4s ISO 100
3X, 7 images, Zerene DMap