Scouleria aquatica

On a recent hike along the Stein River, some of the boulders that were adjacent to or partially submerged in the river had patches of this large, coarse, blackish green moss. The common name for this species is streamside moss. It occupies sites that are partially flooded or splashed by flowing water. It is firmly attached to the rocks so that it can withstand the fast-flowing water.

Scouleria aquatic on boulder by Stein River

Scouleria aquatica on boulder next to Stein River

Scouleria aquatica

When dry, the leaves are folded up against the stem but when they are wet, the leaves spread outwards almost at right-angles to the stem.

Scouleria aquatic dry stem

Scouleria aquatica moist plants with developing capsules

The capsules are unusual for a moss. They are small squat black capsules produced on short stalks. Unlike most mosses, the capsule opening is not lined with teeth.

Scouleria aquatic capsule dry