Cyanide (hydrogen cyanide, HCN) in trace amounts is widespread in the plant kingdom and occurs mainly in the form of cyanogenic glucosides (also called as cyanogens). Cyanogens are glycosides of sugar and cyanide-containing aglycon. These generally taste bitter. Relatively high concentrations are found in certain grasses, pulses, root crops, and fruit kernels. Some cassava varieties are capable of producing over 1 g HCN/kg of fresh tissue. The poisoning generally occurs due to consumption of new and young plants that contain higher amounts compared to the mature ones. Toxicity problems are highly variable and depend on the rate and amount of cyanogenic glucoside consumed, the presence of the β-glucosidase, and detoxification of cyanide. Poisoning and death may occur when an uninitiated animal rapidly consumes a plant with moderate to high levels of cyanogenic glucoside. Chronic problems such as goiter may be caused by long-term consumption of lower levels.