any of a group of vascular plants (tracheophytes) that includes ferns, extinct seed ferns, gymnosperms (conifers, etc.), and angiosperms (flowering plants). Pteropsids manifest a great variety of vegetative and reproductive characteristics. For example, ferns produce spores, and gymnosperms and angiosperms form seeds. The characteristic common to the members of this class is the leaf with branched venation.