Nonembryophytic

Nonembryophytic is a biological term used to describe organisms that do not form embryos as part of their life cycle. In plant systematics, the term contrasts with embryophytic lineages, which belong to Embryophyta—the clade comprising land plants in which the zygote develops into a multicellular embryo that is retained and nourished by parental tissues during early development.

Nonembryophytic groups include most algae and many other non-embryophyte organisms outside the land plant lineage. Among algae, green algae (including groups often referred to as Chlorophyta and some Charophyta), as well as red algae and brown algae, are typically described as nonembryophytic in older or broader classifications. The exact composition depends on the taxonomic framework, because some classifications treat certain algae differently.

Life cycles of nonembryophytic organisms generally lack a multicellular embryo formed within maternal tissue. Fertilization typically produces a zygote that develops directly into a sporophyte or germinates into the next haploid phase, depending on the group, with the embryo absent or not protected by parental tissue.

Evolutionarily, the distinction between nonembryophytic and embryophytic lineages reflects a major innovation in the latter—the protected embryonic development that characterizes land plants. The term is most often used in comparative botany and paleobotany to discuss traits of early plant evolution, and its usage can vary among authors, with some adopting more restricted or broader definitions.