Below them, 30-50m above the ground, is a dense, unbroken canopy of leaves and branches at the top of tall, straight trees. In the gloom beneath is the understorey, where young emergents, small conical trees and shrubs grow. Conifers and cycads Conifers and their close relatives the cycads and ginkgos are among the oldest of all plants, first appearing over 275 million years ago. They are called gymnosperms and all make seeds in cones. Cycads are tropical plants that look a little like palm trees.
Ginkgos are tall Chinese trees.
Silver fir resin is used to make turpentine. Larches are the only deciduous conifers. Sitka spruce provides good wood for paper. Cedar of Lebanon gives a hard, scented wood. Western hemlock is grown for box wood.