Common reed is a cosmopolitan species that can be found on all continents except Antarctica. It is a genetically diverse species with numerous haplotypes identified throughout the world. The lineage recognized as invasive in North America is native to Europe.
European common reed is a perennial grass typically growing 5–15 ft (1½–4½ m) tall from an extensive root system with both rhizomes and stolons. Stems are round and hollow. Leaves are alternate, flat, up to 20 in (50 cm) long, and 1–1½ in (2½–1¼ cm) wide with a tapered tip. Leaves have smooth margins and tend to be bluish-green. Leaf sheaths tightly clasp the stem, and leaf ligules are rimmed by a membranous fringe less than 1 mm long. Flowers are borne in large feathery plumes 6–16 in (15–40 cm) long that are highly-branched and contain numerous spikelets, each containing several individual florets with fluffy, silky hairs. Seeds are narrow ovals 2–3 mm long.
At high stem densities, the introduced European lineage of common reed can displace the native common reed and other native plant species, reduce wildlife food and shelter, block access to water, increase fire potential, and alter the hydrology of wetlands. Negative impacts of European common reed have been documented for several species of plants, birds, fish, and reptiles in North America, including a number of species listed as endangered in the USA and Canada.
Blossey, B. 2023. Common Reed (Phragmites australis,European Lineage): History and Ecology in North America. In: R.L. Winston, Ed. Biological Control of Weeds in North America. North American Invasive Species Management Association, Milwaukee, WI. NAISMA-BCW-2023-38-COMMON REED-P. https://bugwoodcloud.org/resource/files/27702.pdf