Final answer:
Dryopteris and Pteris are types of ferns, while Selaginella is a kind of spike moss, all of which are seedless vascular plants.
Step-by-step explanation:
Dryopteris, Pteris, and Selaginella are examples of seedless vascular plants. Dryopteris and Pteris belong to the Polypodiopsida subclass of Monilophytes, commonly known as ferns. Selaginella belongs to Lycopodiophyta, specifically to the order Selaginellales, also known as spike mosses.
Ferns are well known for their lush green fronds and are ecologically significant due to their ability to colonize damp forest environments. Their reproduction involves spores rather than seeds, which distinguishes them from the seed plants. The ferns and their relatives are primitive vascular plants, meaning they have specialized tissues for water and nutrient transport, yet they lack seeds which differentiates them from flowering plants and conifers.