Mnium hornum

Mnium hornum, also known by the common names horn calcareous moss or swan's-neck thyme-moss, is a species of moss in the genus Mnium.

Description
The upright stems of swan's-neck thyme-moss are 2 to 4 cm tall. Leaves are 4mm to 8mm long, with a toothed border of long, narrow cells. The vein ends a slightly below the tip of the leaf. The lower part of the stem has small, narrow triangular leaves. Capsules are 5mm long, with a lid that narrows abruptly into a short point. The seta is between 2.5 and 5 cm long.

Habitat
Swan's-neck thyme-moss is native to Europe and eastern North America. It is commonly found in damp woodland conditions, especially in acidic soil, such as oak-birch, beech and pine woodlands. It is found on the ground, logs, rocks, tree bases and along streams.

Uses
In 2012, researchers in Serbia found that Mnium hornum could be used as a potential source of arachidonic acid.