Grasses

Grasses
Arabiangrass
Buffelgrass
Cheatgrass
Crimson fountaingrass
Field sandbur
Giant reed
Japanese brome
Johnsongrass
Jointed goatgrass
Lehmann lovegrass
Mediterranean grass
Quackgrass
Ravennagrass
Red brome
Rescuegrass
Ripgut brome
Southern sandbur
Tall fescue
Uruguayan pomps grass
Weeping lovegrass
Wild oat

 

Giant Reed
Arundo donax L. (Grass family, Poaceae)
 

Description

Giant reed is a tall, bamboo-like, perennial grass that can grow to over 30 feet in height; fleshy, creeping rhizomes, up to 3/8 inch thick, form compact masses from which tough, fibrous roots emerge that penetrate deeply into the soil.

Plants: Culms 9-1/2 to 33 feet tall, in large tussocks or hedges; leaves arranged in two vertical rows on opposite sides of the culms, the leaves look like those of corn; ligules very short, less than 1/16 inch long; blades 1 to 3-1/2 feet long, 3/4 to 3-1/2 inches wide, with a wedge-shaped, light to dark brown area at the base.

Inflorescence/Spikelet/Floret: Flowers May to October; panicles are plume-like, 12 to 24 inches long, to 12 inches wide; silver, cream, brown to purplish in color; spikelets 3/8 to 5/8 inch, laterally flattened, with 2 to 4 florets per spikelet; glumes nearly equal, as long as the spikelets, thin, brownish or purplish, 3-nerved, long-acuminate; lemmas 5/16 to 1/2 inch long, 3- to 5-nerved, pilose, hairs 4 to 9 mm, tips 2-toothed, midnerve ending into a delicate awn.

Habitat

Established in moist places such as ditches, stream and riverbanks, and flood plains, growing best in well drained soils where abundant moisture is available; tolerates a wide variety of conditions, including high salinity, and can flourish in many soil types from heavy clays to sands within elevations that generally range below 4,000 feet.

Propagation/Phenology

Reproduces primarily by fast-growing rhizomes that produce new plants; giant reed can float miles downstream where root
and stem fragments may take root and initiate new infestations, sometimes covering several acres.

Comments

Native to the Mediterranean region; giant reed grows rapidly, is highly competitive, and can be difficult to control; plants can rapidly develop dense colonies. New Mexico Watch List species and Texas noxious plant.

Collage of four images

 

 
Forest Service Shield
Invasive plants and weeds of the national forests and grasslands in the southwestern region
Ariabiangrass inflorescence Arabiangrass spikelet Arabiangrass plants Giant reed inflorescence Giant reed plants Giant reed leaf collar region Giant reed infestation of young plants