Similarly, many temperate mosses can survive freezing and thawing without damage. Being prostrate, Bryophytes have much of their surface in contact with the substratum and readily absorb moisture this way. Water often is drawn along the surface of these plants by capillarity and this external water movement is important. In certain mosses, specialised transport cells, hydroids and leptoids, analogous to the xylem and phloem of vascular plants, are found at the centre of the stem. Gases simply diffuse across the plant surface but liverworts also have special pores which are permanently open for gas exchange.
Thallose liverworts are quite distinctive.
They are flattened with a dichotomously branching thallus. This group is absent from drier Caribbean islands like Barbados. Mosses and leafy liverworts can be confused. Click here to see a beautiful pink moss from Sweden. In some Bryophytes, male and female sex organs are borne on separate gametophytes.