Gymnosperms - conifers

Of the two kinds of seed plants, gymnosperms appear much earlier than angiosperms in the fossil record. Gymnosperms lack the enclosed chambers (ovaries) in which angiosperm seeds develop. There are 721 gymnosperm species and four divisions of gymnosperms. Cycadophyta, Ginkgophyta, and Gnetophyta are small divisions. The cycads resemble palms but arent palms, which are flowering plants. The ginkgos have fanlike leaves that turn gold in the fall, and unusual trait for gymnosperms. Gnetophyta have three genera that are probably not closely related: Weltwitschia Gnetum (grows in the tropics as trees or vines), and Ephedra (a shrub in the american deserts. The largest of the four is the conifers.

Division CONIFEROPHYTA
The term conifer comes from the reproductive structure of these plants, the cone. Pines, firs, spruce, larches, yews, junipers, cedars, cypresses, and redwoods all belong to this division of gymnosperms. Most are large trees. Although there are only about 550 species, conifers dominate vast forested regions of the northern hemishpere. Nearly all conifers are evergreens. During the winter, a limited amount of photosynthesis occurs on sunny days. When spring comes, conifers already have fully developed leaves that can take advantage of sunnier days.
The needle shaped leaves of pines and firs are adapted to dry conditions. A thick cuticle covers the leaf and the stomata are located in the pits, reducing water loss. The conifer needle is a megaphyll like all the leaves of seed plants. Coniferous trees are among the tallest, largest and oldest organisms on Earth.