Description: This invasive is a perennial grass with rhizomes that grows up to 2 meters tall. This coarse grass is considered a highly noxious weed globally.
Ecological Threat: This is a rapid growing grass that is competitive with crops. Johnsongrass can be difficult to control and can greatly reduce harvest yields. When stressed by drought, frost, or trampling this grass can produce toxic amounts of hydrocyanic acid. Under these conditions Johnsongrass can be poisonous to livestock upon digestion.
Biology & Spread: Water, wind, and animals can disperse seeds. Tightly enclosed seeds can survive decomposition in the soil for several years. These plants photosynthesize via the C4 pathway
Threat in Oklahoma: This plant poses a threat to crop harvests and displaces native flora.
Management: Weed Control on Rangelands
Image Credit: Jil Swearingen, USDI National Park Service, Bugwood.org - See more at: http://www.invasive.org/browse/detail.cfm?imgnum=0581065#sthash.jwM89qxi.dpuf
Center for Aquatic and Invasive Plants