angiosperma

Angiosperms, or flowering plants, form a large clade of seed plants characterized by production of flowers and fruits containing seeds enclosed within a vessel (ovary). They are the most diverse group of land plants, with more than 300,000 described species, ranging from tiny aquatic forms to large trees.

Key features include flowers with organized floral parts and, in most species, a reduced male and female gametophyte. Pollen reaches the stigma, leading to fertilization and seed formation. A distinctive process, double fertilization, yields both a zygote and endosperm. The ovary matures into a fruit, enclosing the seeds.

Angiosperms occupy nearly all terrestrial habitats and form the basis of many ecosystems. They engage in coevolution with pollinators, dispersers, and soil organisms, promoting diversification. Their diversification during the Cretaceous helped shape modern biodiversity. Major lineages include monocots, eudicots, and magnoliids; relationships are refined by molecular data.

Angiosperms provide staple foods (grains, fruits, vegetables), fibers, medicines, and ornamentals. They support human economies through crops, timber, and horticulture. Their study informs agriculture, ecology, and evolutionary biology.

Fossils confirm angiosperms appeared in the Early to mid-Cretaceous. Today, systematics rely on morphological and molecular data, placing flowering plants into interrelated clades within the angiosperms. Classification is dynamic as new data refine relationships.