- Phragmites australis subsp. australis is a large perennial reed in the grass family that grows from 3-13 ft. (1-4 m) tall. It is a clonal species with stolons and rhizomes. The stem of the native species tends to be more reddish than the nonnative. P. australis subsp. australis is native to Africa, temperate Asia and most of Europe.
- The leaves are 6-16 in. (15-40 cm) long with an open leaf sheath. The nonnative species has a much narrower ligule 0.004-0.02 in. (0.1–0.4 mm) wide, than the native species ligule 0.02-0.04 in. (0.4–1 mm) wide. The foliage on the nonnative is a bluish gray-green, while the native species is more yellowish green. Native species will sometimes have spots on the culms caused by a native fungus to which the nonnative grass is not susceptible.
- The flowers are in a large, feathery, 6-20 in. (15-50 cm) long panicle. The densely flowered panicle has many branches. Panicles in nonnative species are usually denser and more persistent than in native species. The lower glume on the nonnative spikelet is usually shorter 0.1-0.2 in. (2.6-4.2 mm) long, than the native species 0.15-0.3 in. (4-7 mm) long.
- The small seeds are caryopsis as with most grass species.
- Ecological Threat
- P. australis subsp. australis can be found in many shallow water habitats such as coastland, estuarine, lakes, riparian zones, ruderal/disturbed, urban areas, water courses, wetlands. It can form dense monocultures, completely dominating the plant community in a few years.
EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org