angiospermsthe

Angiosperms, or flowering plants, are a clade of seed plants that produce flowers and bear seeds enclosed within a fruit. They are the largest and most diverse group of land plants, with more than 300,000 species in a wide range of habitats.

Key features include the production of flowers, which facilitate sexual reproduction, and fruits, which develop from the ovary after fertilization and help disperse seeds. Their life cycle features double fertilization: one sperm fertilizes the egg to form a diploid embryo, and another fuses with two polar nuclei to form a triploid endosperm that nourishes the developing embryo.

They display a wide range of inflorescence and leaf forms. The gametophyte generation is greatly reduced; the male gametophyte is the pollen grain, and the female gametophyte is the embryo sac within the ovule. Pollination is primarily biotic, involving insects, birds, and other animals, but wind pollination is also common in some groups.

Two major lineages dominate: monocots and eudicots (dicots). Monocots include grasses, orchids, and palms; eudicots include the majority of flowering plants such as oaks, roses, sunflowers, and beans.

Fossil evidence places the origin of angiosperms in the early Cretaceous, with rapid diversification thereafter. They occupy almost every terrestrial habitat and form the basis of many ecosystems and agricultural systems.

Humans rely heavily on angiosperms for food, medicines, fibers, and wood.