Aristotle divided all living things between plants (which generally do not move), and animals (which often are mobile to catch their food). In Linnaeus' system, these became the KingdomsVegetabilia (later Metaphyta or Plantae) and Animalia (also called Metazoa). Since then, it has become clear that the Plantae as originally defined included several unrelated groups, and the fungi and several groups of algae were removed to new kingdoms. However, these are still often considered plants in many contexts, both technical and popular. Indeed, an attempt to perfectly match "plant" with a single taxon is problematic, because for most people the term plant is only vaguely related to the phylogenic concepts on which modern taxonomy and systematics are based.
Verbascum thapsus (Great or Common Mullein) is a species of mullein native to Europe, northern Africa and Asia, and introduced in the Americas and Australia. It is a hairy biennial plant that can grow to 2 m tall or more. Its small yellow flowers are densely grouped on the stem, which bolts from a large rosette of leaves. It grows in a wide variety of habitats, but prefers well-lit disturbed soils, where it can appear soon after the ground receives light, from long-lived seeds that persist in the soil seed bank. It is a common weedy plant that spreads by prolifically producing seeds, but rarely becomes aggressively invasive since its seeds require open ground to germinate. It is a very minor problem for most agricultural crops since it is not a very competitive species, being intolerant of shade from other plants and unable to survive tilling. It however hosts many insects, some of which can be harmful to other plants. Although individuals are easy to remove by hand, populations are difficult to eliminate permanently. It is widely used for herbal remedies with emollient and astringent properties, and especially recommended for coughs and related problems, but also used in topical applications against a variety of skin problems. The plant was also used to make dyes and torches.