Their flagellated sperm cells must swim from the antheridium to the archegonium to fertilize the egg. A tight pack of many moss plants forms a spongy mat that can absorb and retain water. Each plant grips the substratum with rhizoids , elongate cells or cellular filaments. There is an alternation of haploid and diploid generations in the moss life cycle. Contrary to the life cycles of vascular plants, the haploid gametophyte is the dominant generation in mosses and other bryophytes.
Sporophytes are generally smaller and depend on the gametophyte for water and nutrients.
Sometimes have bodies divided into lobes. Have a life cycle similar to mosses. Their sporangia have elaters , coil-shaped cells that spring out of the capsule and disperse spores. Their photosynthetic cells have only one large chloroplast, unlike the many smaller ones of other plants. Regional specialization of the plant body.