Common mullein

Discuss this plant with the guide — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.

Verbascum thapsus

Colorado noxious weed · List C — Manage widespread weeds. CO-rules-2025

Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. Category source · What the lists mean.

Dense rosettes and persistent volunteers. Exposure help.

Identification caveat: Soft leaves do not establish medicinal or ingestion safety. This is not lamb’s-ear (Stachys byzantina).

Still researching this plant

This is a sourced working profile. Evidence is incomplete for People, Dogs & cats, Other animals. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. Uncertainty is not a finding that the plant is safe.

Three views of this plant

Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.

Verbascum thapsus: Tall yellow flowering spike above a column of broad pale woolly leaves. — **habit** — Tall yellow flowering spike above a column of broad pale woolly leaves.
Isidre blanc · CC BY-SA 4.0
Photo source and identification
Original record · Original image
Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other mullein species and hybrids can resemble V. thapsus. Source-labeled V. phlomoides photographs found in gallery searches were not selected.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

Verbascum thapsus: Small yellow flowers and pale woolly buds crowd a dense upright spike. — **flower** — Small yellow flowers and pale woolly buds crowd a dense upright spike.
Fritz Geller-Grimm · CC BY-SA 3.0
Photo source and identification
Original record · Original image
Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other mullein species and hybrids can resemble V. thapsus. Source-labeled V. phlomoides photographs found in gallery searches were not selected.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

Verbascum thapsus: Young basal rosette of thick oval gray-green leaves covered in soft woolly hairs. — **rosette** — Young basal rosette of thick oval gray-green leaves covered in soft woolly hairs.
Borealis55 · CC0
Photo source and identification
Original record · Original image
Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other mullein species and hybrids can resemble V. thapsus. Source-labeled V. phlomoides photographs found in gallery searches were not selected.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

Recognize

A woolly leaf rosette produces a tall, dense spike of yellow flowers, typically in its second year. N-verbascum-thapsus

Plants & habitat

Self-seeds in dry, disturbed places and can crowd neighboring vegetation. Prevent seed formation where control is needed. N-verbascum-thapsus

People

The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.

Dogs & cats

The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.

Other animals

The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.

Before taking action

Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. S27

References

CO-rules-2025 — Colorado Noxious Weed Act rules, 8 CCR 1206-2, Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
N-verbascum-thapsus — verbascum thapsus — Plant Toolbox, NC State Extension. Accessed 2026-09-07T01:04:55+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
S27 — 2103 – Colorado Noxious Weeds, PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.

Content revised 2026-09-07 03:50:00Z · Source checks dated separately in the references.