Moss on a Roof

30 December 2013

Northwest-facing garage/extension roof

Seen in close-up, the concrete rosemary tiles on our garage roof look like the clints and grykes (blocks and fissures) of a limestone pavement.

Wall screw-moss, Tortula muralis, has sporangia with upward pointing 'cranesbill' capsules on a yellow-green filament of a stalk. There are silvery 'guard hairs' on its small dense cushions of fine yellowish/dark green tufts of leaves.

The larger cushion of moss has star-shaped ends to its tufts of bright yellow-green leaves.

In the adjoining clump the leaves of the moss are finer and more tightly packed, giving it a softer appearance.