gymnosperm,

plant ovules: gymnosperm ovule on left, angiosperm ovule (inside
植物学下册 植物实验物实验五,裸子植物2ppt
lecture 12 gymnosperms and angiosperms typepad裸子植物和被子植物
gymnosperm: non-flowering angiosperms: flowering
7. gymnosperm 裸子植物ppt