mosses - non vascular plants forming dense mats and clumps. They are flowerless and the leaves tend to be one cell thick. They do not have seeds. They have spores. They require light to photosyntesis and water, though they have an ability to dry out and then rehydrate and survive. Within the division there are 8 classes Takakiopsida, Sphagnopsida, Andreaseopsida, Andreaeobryopsida, Oedipodiosida, Polytrichopsida, Tetraphidopsida and Bryopsida