Gymnosperms are a group of woody, vascular plants with seeds but without flowers or fruit. The seeds of gymnosperm plants sit exposed on cones rather than enclosed in a fruit as they are with angiosperm plants.
Gymnosperms can grow into magnificent structures and are the largest, tallest and oldest organisms on Earth. Within the gymnosperm clade, there are 4 groups of trees; gingko, gnetophyta, cycads and the largest and most diverse group – the conifers.
The gymnosperms were for a long time the dominant plants on Earth but have been overthrown since the evolution and diversification of the angiosperms. Conifers, however, still dominate in cold and dry environments, as a waxy covering (cuticle) on their needle-like leaves allows them to survive in more extreme conditions than the angiosperms. This is why pine trees tend to become more common towards the poles and at higher elevations where temperatures become colder.
Conifers are a magnificent group of gymnosperm plants that produce seeds without fruit or flowers. They include some incredible trees such as the Giant Sequoias of North America that can grow over 110 m tall.
Gingkos are woody, non-flowering plants. Only one solitary species, Ginkgo biloba, remains on Earth and is found naturally in a small area of China but has been widespread by humans.
Cycads are a small group of around 250 gymnosperm tree and shrub species. They often look similar to palm trees with branchless stems and a crown of leaves at the top of the tree, but they are not at all closely related to palms.
Pines are some of the best known plants around the world. They possess huge economic importance through the timber trade and are easily identifiable due to their characteristic cone-shaped growth form and needle-like leaves.
The gnetophytes are a strange group of plants. They include approximately 70 species of gymnosperms that each exhibit a number of flowering characteristics and are potentially the predecessors to all angiosperm plants.