Several species of poisonous plants are distributed throughout Missouri, and many of them are commonly found in native or improved pastures. A common characteristic of several poisonous plants is a disagreeable taste that ordinarily discourages livestock from grazing them.
Some species are poisonous only during certain stages of growth.
The common cocklebur, a good example, is most poisonous shortly before reaching the two-leaf stage. During this period of growth, cocklebur is exceedingly toxic to pigs but can also harm cattle and sheep. Young second growth sorghum is another example of toxicity during a specific growth period. If livestock poisoning occurs, carefully examine the grazing area for poisonous plants. Shade-loving species include white snakeroot, bracken fern, pokeweed, and buckeye.