Common Mullein pictured, is a biennial that does not make a seed until its second year of life. It has a long fibrous taproot, which makes hand pulling and chopping effective methods of control. A mature plant will be anywhere from two to six feet tall once it is fully grown, with bright yellow flowers. Common Mullein is invasive in non-cropland areas and thrives in dry weather. Livestock find it unpalatable due to its heavy pubescence. It has been found along the railroad tracks and Old Highway 10 in western Billings County.