Arundo donax L.
Arundo donax L.Elephant Grass, Giant Reed
| Threat Level | Category |
|---|---|
| Emerging | Grass |
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Similar Species May be confused with the following native and/or non-native species. Landscape Alternatives lists native horticultural substitutes |
Phyllostachys aurea Phragmites australis Landscape Alternatives |
|---|
Description
Height
Giant reed grass has cornlike stems and forms thickets in distinct clumps to 20 feet (6 m) in height spreading from tuberous rhizomes. Dried grass remains standing in winter and spring.Stem
Giant reed stems are somewhat succulent and fibrous, with a round cross section to 1 inch (2.5 cm). Stems are hairless, gray to yellowish green, solid jointed every 1 to 8 inches (2.5 to 20 cm), and covered by overlapping leaf sheaths. Initially white pithed, they becoming hollow between joints. Old stems sometimes persist into the following summer.Leaves
Alternate, cornlike leaves are long lanceolate, 18-30 inches (45-76 cm) long and 1-4 inches (2.5-10 cm) wide near base, with both surfaces hairless. Each leaf clasps the stem with a conspicuous whitish base, juts out from the stem and droops at the end. Margins and ligule are membranous (about 1 mm). The midvein is whitish near base becoming inconspicuous towards tip. Veins are parallel. Sheaths overlap and are hairless and semi-glossy.Flowers
From August to September, giant reed grass produces terminal, erect, dense plumes of whorled, stemmed flowers to 36 inches (1 m) long. Husks are hairy and membranous with several veins and greenish to whitish to purplish.Seeds
October to March. The dense terminal plume is spindle-shaped, densely hairy. Since it is infertile, a grain never appears.Images
Photo: Chuck Bargeron, University of Georgia, Bugwood.orgMore images of Arundo donax
Life History
Giant reed grass has cornlike stems and forms thickets in distinct clumps to 20 feet (6 m) in height, with gray-green and hairless stems, long-lanceolate leaves alternately jutting from stems and drooping at the ends, and large plumelike terminal panicles. Seeds are infertile. It spreads from tuberous rhizomes. Dried grass remains standing in winter and spring. It is a member of the Poaceae or Grass family.Ecology and Habitat
Giant reed grass occurs mainly on upland sites as scattered dense clumps along roadsides and forest margins, migrating from old home plantings by displaced rhizome fragments. Densely branching, tuberous rhizome growth results in persistent infestations. Spread is probably enhanced by movement of stem parts in soil or by road shoulder grading. Plants are believed to be sterile and do not produce viable seeds.Origin and Distribution
Giant reed grass was introduced from western Asia, northern Africa, and southern Europe in the early 1800s. It has been used as an ornamental.Other states where invasive: AZ, CA, GA, MD, NM, NV, TX, VA. Federal or state listed as noxious weed, prohibited, invasive or banned: TX.
Source: Information on this plant page is derived primarily from James H. Miller's Nonnative Invasive Plants of Southern Forests, USDA Forest Service.
Management Recommendations
Herbicical Control
Foliar Spray Method
Thoroughly wet all leaves with one of the following herbicides in water with a surfactant (September or October with multiple applications to regrowth):A glyphosate herbicide as a 2-percent solution (8 ounces per 3-gallon mix)
Arsenal AC as a 1-percent solution (4 ounces per 3-gallon mix)
A combination of the two herbicides
Nontarget plants may be killed or injured by root uptake.