The word Bryophyta is formed from the Greek words bryon meaning moss and phyton meaning plant. Bryophyta means mossy plants. Bryophytes are green avascular plants composed of parenchyma cells, divided into thalloids or stems and leaves. The division of bryophytes is called Bryophyta. In 1864 scientist Braun first used the term Bryophyta. Plants of the class Bryophyta are called amphibious plants as water is essential for fertilization and life cycle. The smallest bryophyte is Zoopsis argentea. Zoopsis is 5 mm in length. And the largest bryophyte is Dawsonia. The length of Dawsonia is 50-70 cm (Dawsonia superba, Dawsonia longifolia Dawsonia longiseta).