Tortula ruralis

 

Sidewalk moss is one of the most common mosses in grasslands and dry forests in the Southern Interior. When moist it forms softe green clumps often with red and white highlights.

When it is dry, it can look very different and appear as bronwish-black clumps with white highlights.

The leaves are distinctive and have an area of clear enlarged cells near the base of the leaf. The margins of the leaf are slightly rolled under and the tip of the leaf has a long clear hairpoint.

The clear hairpoint is coarsely toothed.

This is a cross-section of the leaf. The leaves are only one-cell layer thick except along the thick midrib that runs along the length of the leaf.

The plants have a dull appearance even when moist. This is because the cell walls of the individual cells are covered in severl small bumps called papillae which reflect the light in different directions. Many mosses have smooth leaf cells and lack these bumps and so often appear shiny in appearance.

The capsule mouth is unusual. Most mosses have 8 or 16 teeth surrounding the opening of the capsule which usually bend outwards when the capsule is dry and help disperse the spores. In sidewalk moss, the “teeth” form a long fragile spiral tube of long spaghetti-like teeth.

The next time you are out in the grasslands after a rain and see patches of a fairly large moss, you are more than likely looking at sidewalk moss.