Genus PleuroziumHYPNUM Sub-genus PLEUROZIUM
The species of this sub-genus increase yearly by arched branches or by rigid erect growths, the branches are short, unequal, and grow outward from the main stem, a character which suggested the name Pleurozium, a compound of the Greek for; a side, and; a branch.
The leaves on the stem are larger than those on the branches, and are different in shape. Besides these leaves there are numerous large and many-parted leaf-like organs (paraphyllia).
The other characters of this sub-genus are similar to those of the genus Hypnum.