Poisonous arrow grass is found in all the western states and both sheep and cattle may be poisoned by it.
Species of arrow grass that poison livestock are widely distributed in marshy pastures and native grass hay areas throughout the United States.
As long as arrow grass has adequate moisture, it does not cause poisoning.
Poisonous arrow grass grows best in soil covered with water.
How much arrow grass does it take to poison sheep or cattle?
About 1/50 of an ounce of hydrocyanic acid of stunted arrow grass will kill a 600 pound animal.