Use this domain for mosses (phylum Bryophyta, class Musci), liverworts (phylum Bryophyta, class Hepaticae), fungi (phylum Thallophyta, subdivision Fungi), algae (phylum Thallophyta, subdivision Algae), and lichens. These plants do not have true roots, stems, or leaves. The mosses are small, green, flowerless plants that grow in moist environments and look like velvety or feathery growths carpeting the ground, tree trunks, and rocks. The liverworts are similar to the mosses with a flat and branching growth pattern. The algae possess green chlorophyll. They vary from one-celled organisms, which sometimes live in colonies such as pond scum, to complex organisms such as seaweed. The fungi do not possess chlorophyll and feed off of other organic material. Lichens consist of a fungus and an algae growing together. They commonly grow on trunks of trees and rocks. Some are flat and leafy, and some are moss like.