Moss

Mosses and liverworts are traditionally classified together in the Division Bryophyta on the basis of their sharing: •a similar life cycle (alternation of generations) •similar reproductive organs (antheridia and archegonia) •lack of vascular tissue (xylem and phloem) Some 23,000 species of living mosses and liverworts have been identified. These are small, fairly simple, plants usually found in moist locations. •Liverworts have a thin, leathery body that grows flat on moist soil or, in some cases, the surface of still water. The photo (courtesy of William C. Steere and AIBS Bulletin) is of a common liverwort, Ricciocarpus natans. •Mosses have an erect shoot bearing tiny leaflike structures arranged in spirals.