I know this as the Common Mullein (Verbascum Thapsus), and have had it growing off and on in my yard, but it has never been invasive. It has many other common names such as: Aaron’s rod, Adam’s flannel, feltwort, Jacob’s staff, old man’s flannel, blanket leaf, bullock’s lungwort, cow’s lungwort, hare’s beard, lady’s foxglove, ice leaf, Peter’s staff, shepherd’s club, candlewick, flannel leaf, flannel mullein, flannel plant, hedge taper, Indian tobacco, Jupiter’s staff, torch-wort, velvet dock.
Great mullein is a biennial which reaches a height of 6′ or more in the second year, thoroughly deserving the name, though in the first year it has a totally different form and apparently different leaves, as they are thickly coated in fuzz, rather like lamb’s ears. The pale grey leaves are covered with silver and felt like hairs. The flowers are yellow by nature and occupy approximately half of the stem.
Mullein flowers from November through March and is considered by many agricultural businesses to be a weed and more of a nuisance than anything. Although unlikely to become invasive except in areas with little competition or after forest fires, it is listed as a noxious weed in Colorado, Hawaii and Victoria, Australia. Because each plant produces a huge number of seeds which can lie dormant for up to 100 years, it is very difficult to eradicate completely.
The Mullein is native to Europe, northern Africa and Asia, and has been introduced medicinally to the Americas and Australia. It has the ability to grow in a vast range of habitats but prefers well lit and disturbed soils, helping to enable its appearance soon after the ground receives light.
It is the mullein leaves and flowers that are used medicinally but the mullein root is said to aid with bladder incontinence. Fresh mullein leaves are also used for the purpose of making a homoeopathic tincture. Oil is made from the leaves and flower for medical purposes.
I have included an herbal site that may be of interest to you: