This is a widespread, variable, circumboreal species that appears native in wetlands of more northern and western regions in North America; 2n = 27-42 but mostly 28 (FNA 24). It has been considered native in eastern states (Braun 1967; B, Ch, D, F, HFG, J, SC, Sm, W), but some local uncertainty remains (Lyons 2010). European cultivars have been introduced for forage and soil stabilization, perhaps interbreeding with native races (Merigliano & Lesica 1998; Lavergne & Molofsky 2007, Kettenring et al. 2019). P. arundinacea is often considered invasive due to its vigorous rhizomatous spread, but such behavior may be influenced by beavers and other large herbivores; see also notes under Lythrum salicaria. Cattle can greatly reduce it within one season (Brummer & Moore 2000, Paine & Ribic 2002, Norland et al. 2022), but deer alone may not be able to reduce it (Kellogg & Bridgham 2004). Plants contain relatively large and diverse amounts of alkaloids in the indole (gramine*), tryptamine (DMT), phenylalanine (hordenine) types and others; these can influence palatability (Simons & Marten 1971, Østrem 1987). The few other Poaceae with similar chemistry are also generally nutritious, and these alkaloids may act to reduce herbivory: Hordeum*, Dactylis, Arundo*, Echinochloa and Zea (Kokubo et al. 2017). Burning in spring can largely remove P. arundinacea, but summer burns can greatly increase it (Howe 1995). In Ky. the species was first reported by Riddell (1835; as "americana Ell."), but was omitted by Anderson (1924) and rarely collected before the 1970s. It is locally abundant along marshy margins of large or small streams and in remnants of natural wetlands, especially on eutrophic sites. It also occurs in mined areas, roadside ditches or similar disturbed sites without clear natural heritage. There is no recent record of planting for forage or other purposes, but seed was apparently distributed for sale a century or more ago. Gm stated: "a persistent perennial, the seeds of which are frequently brought into this country from Europe, but believed native to the United States." He did trials for forage at the Univ. of Ky. ca. 1894-1899 with mixed results, and noted: "adapted to rather low wet ground... it can be made useful in binding the soil of embankments." The sterile European cultivar known as "ribbon-grass", forma variegata (Parnell) Druce or var. picta L. occasionally persists or escapes from gardens.