GymnospermsConifers are the most common and widespread type of gymnosperms. Gymnosperm literally means "naked seed"
and alludes to the fact that the plants’ seeds are borne exposed. (As opposed to the
angiosperms, which bear their seeds within a protective structure, the ovary.) In the
conifers, these seeds are borne in cones.
Conifers include the familiar pines, spruces, firs,
cedars, junipers, and cypress, as well as the largest living things on earth—the
giant sequoias. Members of this group are favored by gardeners for their rich foliage and
bark colors and interesting textures, and because many species are evergreen. In addition,
conifers are the source of much of our lumber and paper products.
Conifers and other gymnosperms such as cycads and ginkgos
represent an evolutionary step up from the ferns, and not only because they protect their
developing embryos in seeds. Unlike the seedless plants, gymnosperms don’t require
water to transport sperm to egg, allowing them to freely colonize dry environments. In
addition, these plants possess a vascular cambium, which allows them to form secondary
xylem, or wood. Therefore, gymnosperms can grow much larger than the more primitive plants
which, lacking a vascular cambium, remain herbaceous.
white pine cone
scale with seed (enlarged)
