Gymnosperms 1:The gymnosperms are four related phyla of seed-producing plants; their seeds, however, lack the protective, outer covering that surrounds the seeds of flowering plants. Typically,
gymnosperms are woody, perennial shrubs or trees, with stems, leaves, and roots, and a well developed vascular (transportat) system. The reproductive structures in most gymnosperms are cones: male cones produce microspores in which male gametes (sex cells) develop; female cones produce megaspores in which female gametes develop. Microspores are blown by the wind to female cones, male and female gametes fuse during fertilization, and a seed develops. The four gymnosperm phyla are the conifers (phylum Coniferophyta), mostly tall trees; cycads (phylum Cycadophyta), small palmlike trees; the ginkgo or maidenhair tree (phylum Ginkgophyta), a tall tree with bilobed leaves; and gnetophytes (phylum Gnetophyta), a diverse group of plants, mainly shrubs, but also including the horizontally growing welwitschia.
