Aquatic Moss

Species: Sphagnum spp., peat moss, sphagum
Family: Sphagnaceae

Mosses, as well as liverworts, belong to a plant group called Bryophytes. The Bryophytes are characterized by having no specialized food and water transport tissues. They lack flowers, true leaves, stems, or roots, but they do have analogous structures. Peat moss is unique in that it can hold large quantities of water inside its cells. Some species can hold up to 20 times their dry weight in water which is why peat moss is commonly sold as a soil amendment. Peat moss can acidify its surroundings, and is commonly found in bogs and fens.

Individual peat moss plants consist of a wiry main axis with small clusters of soft, floppy side branches. The top of the plant has compact clusters of young branches. The side branches consist of a series of more-or-less overlapping, cup-shaped, or spear-shaped "leaves". Some species have thick, water-swollen "leaves" and a correspondingly plump appearance, while other species hold smaller amounts of water and thus have a thinner, stringier appearance.

Aquatic Moss Icon
Leaf: Lacks true leaves. Peat mosses have leaf-like structures with two kinds of cells; small green living cells and large clear structural dead cells. They are spoon shaped or spear shaped and are clear, green, yellowish or reddish.

Stem: Lacks a true stem. The brown, black or yellowish main axis is thin, wiry, and upright.

Flower: Flowers are not produced. Spores are released from specialized black, shiny capsules located at the tips of thin stalks. 

Fruit: Mosses lack fruits. Spores are produced in capsules.

Root: No true roots. Branched filaments, called rhizoids, develop on some species and serve to anchor plants to the substrate.

Propagation: Spores and fragmentation.

Importance of plant: Used as a soil amendment, packing material, absorbent, and fuel. Historically used as bandage material because of its acidic, antibacterial quality.

Distribution: Peat moss species found in Washington are found primarily in the Northern Hemisphere.

Habitat: Bogs and fens; often forms mats on bog surfaces.

May be confused with: Other moss species. Peat moss can be distinguished by its unique branch clusters. The plant color, the shape of the "leaves" growing around the "stems," and the shape of the green cells are characteristics used to identify peat moss to species.

Photographs: Closeup of Sphagnum sp. plants

Line Drawings: Sphagnum sp. 

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