What is the simplest plant?
Mosses, like the other bryophytes (liverworts and hornworts), are an ancient group of simple plants dating back some 360 million years. They represent an evolutionary step up from algae, the simplest plants in the plant kingdom. The four major groups of plants are ferns, mosses, gymnosperms, and flowering plants. These groups have evolved at different times when earth had many different climate and ecological conditions.