Metzgeriales

Metzgeriales is an order of liverworts. The group is sometimes called the simple thalloid liverworts: 'thalloid' because the members lack structures resembling stems or leaves, and 'simple' because their tissues are thin and relatively undifferentiated. All species in the order have a small gametophyte stage and a smaller, relatively short-lived, spore-bearing stage. Although these plants are almost entirely restricted to regions with high humidity or readily available moisture, the group as a whole is widely distributed, and occurs on every continent except Antarctica.