About Hypnum cupressiforme Hedw.
Hypnum cupressiforme, commonly known as cypress-leaved plaitmoss or hypnum moss, is a common and widespread moss species belonging to the genus Hypnum. It can be found on all continents except Antarctica, and occurs in a very wide variety of habitats and climatic zones. It typically grows on tree trunks, logs, walls, rocks, and other surfaces. It prefers acidic environments and is fairly tolerant of pollution. It was formerly used as filling for pillows and mattresses; the association with sleep is the origin of the genus name Hypnum, which comes from the Greek word Hypnos. This small to medium-sized moss reaches about 2–10 cm in length. It is pleurocarpous, with prostrate, creeping stems that form smooth, dense mats. Its branched stems are covered in overlapping leaves, giving an appearance that resembles a cypress tree. The stem leaves are long and thin, measuring 1.0–2.1 mm by 0.3–0.6 mm. They are concave and sickle-shaped, tapering toward the tip. The branch leaves are smaller and narrower than the stem leaves. This moss produces short, cylindrical, slightly curved capsules that contain its spores. These capsules measure 1.7–2.4 mm in length, and have a lid-like operculum that measures 0.6–0.9 mm. The capsules are borne on reddish-brown stalks that are 1–2.5 cm long. This moss is dioicous, meaning it has separate male and female plants. Numerous varieties of Hypnum cupressiforme have been described, which makes this a highly variable species.
