[Solved] What does system lockup and page fault indicate? Gnetophytes: A group of seed plants that are characterized by unique features distinguishing them from other gymnosperms, with three distinct genera: Gnetum, Welwitschia, and Ephedra. Angiosperms: A large group of flowering plants whose seeds are enclosed within a fruit, comprising a vast majority of plant species. Gymnosperms: A group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes, characterized by having naked seeds not enclosed in an ovary. Naked Seeds: Seeds not enclosed in an ovary or fruit, typical of gymnosperms like pine trees.