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Giant Reed

Arundo donax

Plant: Giant reed grass, thicket-forming in distinct clumps, to 20 ft (6 m) tall, gray-green and hairless stems, long-lanceolate leaves alternately jutting from stems and drooping at the ends, large plume-like terminal panicles in late summer persisting through winter, from tuberous rhizomes.

Stem: Round in cross-section, to 1 in (2.5 cm) in diameter, somewhat fleshy and fibrous, covered by overlapping leaf sheaths, gray- to yellowish-green, solid jointed every 1-8 in (2-20 cm), white pith initially becoming hollow between joints.

Leaves: Alternate, corn-like, clasping stem with conspicuous whitish base, midvein whitish near base becoming inconspicuous towards apex, veins parallel, blades long lanceolate, 18-30 in (45-75 cm) long and 1-4 in (2.5-10 cm) wide near base, hairless both surfaces, margins and ligule membranous (about 1 mm), sheaths overlapping, hairless and semi-glossy.

Flowers: Aug-Sep. Large terminal erect plumes, to 36 in. (1 m) long, greenish to whitish to purplish, hairy, dense
November (J. Miller)

July (J. Miller)
flowered on whorled branches from a gray-green stem, husks membranous and several nerved.

Seeds: Oct-Mar. Dense terminal plume, spindle-shaped, densely hairy, but grain never appears, sterile.

Ecology: Occurs mainly on upland sites. Scattered dense clumps along roadsides and forest margins, escapes from old homesite plantings, migrating by displaced rhizome fragments. Plants believed to be sterile and not producing viable seeds. Persistent infestations that expand by rhizome growth.

Resembles golden bamboo (Phyllostachys aurea) being a large grass-like plant, but not bamboo in character. Closely resembles common reed (Phragmites australis), difficult to differentiate a part, which occurs mainly in near swamps and marshes near the coasts and wet habitat having hairy seed heads but not erect, but fan in a loose plume.

Exotic Pest Plant Control Recommendations

Bayer International Code - ARDO4
FIA Code - 4008

June (J. Miller) December (J. Miller)


June (J. Miller) August (J. Miller)

* USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. February 5, 2002.
States with suspected
infestations are shown in red.*
line
USDA Forest ServiceUSDA APHIS PPQ The Bugwood Network University of Georgia Invasive.org is a joint project of
The Bugwood Network, USDA Forest Service & USDA APHIS PPQ.
The University of Georgia - Warnell School of Forest Resources and
College of Agricultural and Environmental Sciences - Dept. of Entomology
Last updated on Sunday, August 10, 2003 at 11:14 PM
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