Family: Poaceae, Grass view all from this family
Description Introduced. A perennial grass that spreads rapidly by way of creeping rhizomes and forms dense arching stands.
Flowers: open, green to purplish, drooping panicle, 4-20" (10-50 cm) long. Glumes (bracts) encasing seeds are shiny and brown to black.
Leaves: linear, narrow; blades 4-20" (10-50 cm) long, 1/4-3/4" (0.5-2 cm) wide.
Height: 6-7' (2 m).
Warning Sorghum plants can accumulate toxic levels of cyanide-producing compounds, especially if they are damaged by frost, drought, or trampling, and can poison livestock. They can also accumulate toxic levels of nitrates.
Habitat Disturbed habitats, such as roadsides, fields, orchards, croplands, irrigation ditches; reported in some native grasslands and riverside habitats.
Range Native of Asia and the Mediterranean region; introduced and naturalized in North America.
Discussion Johnsongrass is a wide-ranging agricultural pest and is considered one of the world's ten worst weeds. It is widely classified as a noxious weed in the United States, where it has been recorded in nearly every state. It spreads by creeping rhizomes (as well as by seeds) into crops, and can reduce harvest yield. It is also a bothersome hay fever plant for many people.