Sphagnum can hold up to 20 times its dry weight in water. This is due to the large clear water holding cells. Sphagnum has dichotomous branching and has a pennulus coming off the branch. There is a capitulum at the very top of the moss plant and the leaves are three ranked. There are no rhizoids.
Reproduction occurs in the dominant gametophyte stage.
They can be either monoecious or dioecious, containing both antheridia and archegonia. Added to soils, the peat helps the soil to retain water. It is also used as packing materials for plants. The Class Andreaeopsida consists of only a single order and family, and only two genera. The one species in particular that has been much described is Andreaea , which contains more than 100 species.