With the start of fall comes the risk of cyanide poisoing in ruminants. Cyanide, prussic acid, hydrogen cyanide or hydrocyanic acid poisoning are all terms describing the same condition. A number of common plants, including sudangrass, johnsongrass, sorghums and sorghum-sudangrass hybrids contain cyanogenic glycosides in the outer cells of the plant. Further inside the leaf tissue are the enzymes needed to convert these compounds to the cyanide poison.