Grimmia pulvinata

Grimmia pulvinata grows in a small, cushion-like shape, around 1–2 cm (0.39–0.79 in) tall. Its color ranges from a grey-green to an orange-yellow.^[5] Its leaves are lanceolate, being broad and oval-shaped at the base and very narrow toward the tip.^[6] They may show a silvery hue near the tip in some specimens. Its capsules are oval-shaped, and bend back into the leaves when the plant is dry, and stand out when it is moist.^[5]

Grimmia pulvinata colonizes a variety of surfaces including rocks, concrete, and tree trunks. It is tolerant of a wide range of pH levels on surfaces, allowing it to live on many types of rock.^[7]

However, it prefers surfaces such as old mortar and tree trunks.^[8]

Grimmia pulvinata is the most common species in the genus Grimmia, with a nearly worldwide distribution.^[7] It is particularly common in Britain^[9] and the west coast of North America.^[10] It lives primarily in temperate regions, from sea level to elevations up to 9,800 ft (3,000 m).^[7]

Grimmia pulvinata is a pioneer species, meaning it is among the first organisms to colonize habitat which has been disturbed by an event, such as a forest fire.^[6] Its resistance to pollution allows it to colonize urban areas, such as roofs, walls, and tarmac.^[5]