Liverworts and mosses are small,low-growing plants that belong to the phylum Bryophyta. Bryophytes do not have true stems, leaves, or roots (they are anchored to the ground by rhizoids), nor do they have the vascular tissues (xylem and phloem) that transport water and nutrients in higher plants. With no outer, waterproof cuticle, bryophytes are susceptible to drying out, and most grow in moist habitats. The bryophyte life-cycle has two stages. In stage one, the green plant (gametophyte)
produces male and female gametes (sex cells), which fuse to form a zygote. In stage two, the zygote develops into a sporophyte that remains attached to the gametophyte. The sporophyte produces spores, which are released and germinate into new green plants. Liverworts (class Hepaticae) grow horizontally and may be thalloid (flat and ribbonlike) or “leafy.” Mosses (class Musci) typically have an upright “stem” with spirally arranged “leaves.”
