Common Mullein (Verbascum thapsus) is native to Europe, northern Africa, and Asia. It’s a biennial that shows up in most of North America. In Canada, Common Mullein is found in all the southern provinces. In the US, it occurs in all the contiguous states and Alaska and Hawaii.
Seeds of Common Mullein remain viable for decades while each plant can produce anywhere from 180,000 to 240,000 seeds. Dispersal of the seeds requires the seed capsules which remain attached to the stem to be moved either by the wind or an animal. Most of the seeds remain very close to its parent plant.
The flowering spike of the Common Mullein which ranges in size from approximately 6 to 24 inches makes me think of corn on the cob. Each of the flowers when open is about 3/4 inch across. The flowers open randomly and stay open just one day. Though Common Mullein tries very hard to irritate me by showing up in my gardens, it’s not difficult to get rid of. Just put a shovel to the ground and let it know it’s not welcome. Very simple.