Bryophyte
Bryophyte is a traditional name used to refer to all embryophytes (land plants) that do not have true vascular tissue and are therefore called "non-vascular plants". Some bryophytes do have specialized tissues for the transport of water; however, since these do not contain lignin, they are not considered to be true vascular tissue.As of 2014, it is uncertain whether bryophytes are a natural or monophyletic group or a paraphyletic group, but the name is convenient and remains in use as a collective term for mosses, hornworts, and liverworts. Bryophytes produce enclosed reproductive structures (gametangia and sporangia), but they produce neither flowers nor seeds, reproducing via spores. The term "bryophyte" comes from Greek βρύον, bryon, "tree-moss, oyster-green" + φυτόν – phyton "plant".
Life cycle
Like all land plants (embryophytes), bryophytes have life cycles with alternation of generations. A haploid gametophyte, each of whose cells contains a fixed number of unpaired chromosomes, gives rise to a diploid sporophyte, each of whose cells contains twice the number of paired chromosomes. Gametophytes produce haploid sperm and eggs which fuse to form diploid zygotes that grow into sporophytes. Sporophytes produce haploid spores by meiosis, that grow into gametophytes.
