Archegoniates

Archegoniates are a group of plants that reproduce sexually through structures called archegonia and antheridia. Archegonia are the female reproductive organs, each containing a single egg cell. Antheridia are the male reproductive organs, producing numerous sperm cells. This group includes bryophytes (mosses, liverworts, and hornworts), pteridophytes (ferns and their allies), and some gymnosperms. In these plants, the gametophyte generation is typically prominent, and the sporophyte generation is dependent on the gametophyte. Fertilization requires water for the sperm to swim to the egg. The development of the embryo within the archegonium is a key characteristic, hence the term "archegoniate." This reproductive strategy represents a significant evolutionary step from algae, allowing for greater protection and nourishment of the developing young sporophyte. While some modern gymnosperms retain archegonia, their life cycles are more gametophyte-dominant than seed plants like angiosperms, which have a greatly reduced gametophyte generation and no archegonia. The term "archegoniate" is sometimes used to distinguish these plant groups from those that lack these specific reproductive structures.