bio

Gymnosperm

Seed plants whose ovules are not enclosed in a sealed carpel — conifers, cycads, ginkgo, gnetophytes. The name means "naked seed", and it is accurate: the seed develops exposed on a cone scale rather than inside a closed chamber. The group dominated terrestrial floras through the Mesozoic and is now down to relatively sparse lineages. A notable correction: an older hypothesis made the Gnetales the closest relatives of the flowering plants, based on cone and vessel resemblances. Molecular data showed those resemblances were convergent — the Gnetales are conifers, and the flowering plants are a branch of their own.