Late autumn is the best time to see this very common species, when it usually bears numerous horizontal capsules, each of which has a lid with a long, narrow beak, as is typical of Rhynchostegium and Rhynchostegiella species. Both generic names stem from the word rhynkhos, which means snout in Greek.
It is not however hard to find at other times of the year if you make yourself familiar with its favoured habitats – deeply shaded, dry but sheltered situations on hard basic substrates. In fact, it will often grow where little else will, as for example at the base of a wall on mortar. It does grow on natural rock too, but seems to really like walls and other man-made habitats.Read the Field Guide account