Bryophytes are all embryophytes ('lan plants') that are non-vascular: they have tissues and enclosed reproductive systems, but they lack vascular tissue that circulates liquids. They neither have flowers nor produce seeds, reproducing via spores. The term bryophyte comes from Greek βρύον - bruon, "tree-moss, oyster-green" < βρύω - bruo, "to be full to bursting, to abound" + φυτόν - fyton "plant".