The answer is vascular and nonvascular seedless plants. Seedless plants can be organised in two groups: 1. Vascular seedless plants, such as Ferns, Clubmosses, and Horsetails, and 2. Nonvascular seedless plants, such as Mosses, Hornworts, and Liverworts. The main difference is the presence and organisation of vascular tissues. Vascular plants have vascular tissues consisting of xylem and phloem for water and nutrient transportation. Nonvascular plants have simple tissues specialised for internal water transport.
