All the plants of the world are divided into two groups based on having flowers. Phanerogams are plants and cryptogams are plants. The non-flowering or cryptogamous are divided into three categories. Thallophyta, Bryophyta and Pteridophyta. Thallophyta are immature cryptogams. Bryophyta and Pteridophyta are hybrid cryptogams. Bryophyta are connecting plants between Thallophyta and Pteridophyta.