In the past the mosses, liverworts, and hornworts were grouped together because of similarities in reproduction, form, and habitat. However, now scientists realize that they did not arise from common ancestors.
Bryophytes are small in size and require water outside the plant for reproduction.
The gametophytes of mosses consist of small leaves spirally arranged around a stem-like axis. Attached to their roots are rhizoids that help mosses absorb water. However, most of the water used by the plant uses capillarity to travel up the outside of the plant. Moss leaves are only one cell thick, they do not contain vascular strands or stomata, and all of the cells are haploid.