Wall Screw Moss

Tortula muralis

Date First Recorded in the Garden: 30/08/2021

Family Pottiaceae: One of the largest known families of moss in the world, accounting for over 10% of the known species.

Wall Screw Moss – Tortula muralis

A very common moss, surely found in all towns and cities, as it is happy to establish on garden walls and stone surfaces. Particularly on base rich materials, including concrete.

Of course growing on hard upright surfaces has the disadvantage of exposure to dry sunny conditions, depending on the aspect and location of the wall. The moss can appear almost fuzzy and silver due to its nerve (a central vein like structure of thickened cells that runs up the centre of its leaf like structures), extending beyond the end of the leaf (known as being excurrent) and forming a silver hair. This can clearly be seen in the image above. According to the New Naturalist 2005 book on Mosses & Liverworts (p.106) *, the excurrent hair helps protect the moss from sunlight and trap moisture. The same book also explains how the spore capsule contains around 400,000 spores per capsule.

In the Garden

True to form, we tend to find this species on the concrete steps along with one or two other moss species. Although noted as first recorded in August 2021 when this website began, this species has been present since we moved into the property in 2000 and probably since the property was built. Like all mosses so far looked at it supports a micro fauna of mites and springtails.

*Porley, R. Hodgetts, N. (2005) Mosses & Liverworts. New Naturalist . HarperCollins Publishers, London.