Western Asia and Indo-Pakistan region
Giant reed is a perennial grass typically growing 6½–26 ft (2–8 m) tall from a rhizomatous root system. Stems are round, S–1½ in (1–4 cm) in diameter, and hollow between nodes. Leaves are alternate and very distinctly two-ranked, growing in a single plane. Leaves are a pale blue-green, typically 1–2 ft (30–60 cm) long, and taper to a fine tip. The leaves clasp the stem and have fine tufts of hair at the base. Flowers are borne in large feathery plumes 1–2 ft (30–60 cm) long. Seeds are often absent or are sterile.
Giant reed forms massive stands in riparian areas, displacing native plants and animals (both terrestrial and aquatic), consuming scarce water resources, and increasing wildfire threats. Large infestations alter channel morphology, increase erosion, facilitate the spread of cattle fever ticks, and impede law enforcement activities on the international border of Mexico and the USA.
Moran, P.J. and J.A. Goolsby. 2022. Giant Reed (Arundo donax): 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-2022-37- GIANT REED-P. https://bugwoodcloud.org/resource/files/23208.pdf