[Solved] Barbarian invasions caused the collapse of the ancient world. 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. Conifers: A group of cone-bearing seed plants with vascular tissue, mostly evergreens, that includes pines, spruces, and firs. Gymnosperms: A group of seed-producing plants that includes conifers, cycads, ginkgos, and gnetophytes, characterized by seeds that are not enclosed in an ovary.