Spermatophyte

Spermatophytes, also known as seed plants, are a clade of embryophytes that produce seeds. They are the dominant group of plants on Earth, comprising over 300,000 species. Spermatophytes include both gymnosperms and angiosperms.

Characteristics

Spermatophytes are characterized by the presence of seeds, which are the result of sexual reproduction. Seeds contain an embryo, a supply of nutrients, and are encased in a protective coat. This adaptation allows spermatophytes to survive in a variety of environments and to disperse their offspring over long distances.

Gymnosperms

Gymnosperms are seed plants that do not form flowers. Their seeds are typically exposed on cones or other structures. Major groups of gymnosperms include conifers, cycads, ginkgos, and gnetophytes.

Angiosperms

Angiosperms are seed plants that produce flowers and form seeds enclosed within a fruit. They are the most diverse group of plants, with over 250,000 species. Angiosperms are divided into two main groups: monocots and dicots.

Evolution

The evolution of spermatophytes marks a significant transition in the history of plant life. The earliest seed plants appeared in the late Devonian period, around 360 million years ago. The development of seeds allowed these plants to reproduce without the need for water, unlike their bryophyte and pteridophyte ancestors.

Importance

Spermatophytes play a crucial role in ecosystems and human life. They are the primary producers in most terrestrial ecosystems, providing food and habitat for a wide range of organisms. Many spermatophytes are also important agricultural crops, such as wheat, rice, and maize.

Related Pages

• Plant
• Embryophyte
• Gymnosperm
• Angiosperm
• Monocotyledon
• Dicotyledon
• Conifer
• Cycad
• Ginkgo
• Gnetophyte