Elongated mustard
Discuss this plant with the guide — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
Brassica elongata
Colorado noxious weed · List A — Eradicate. CO-rules-2025
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. Category source · What the lists mean.
Early detection priority in dry disturbed land. Exposure help.
Identification caveat: Reference photographs identify B. elongata subsp. integrifolia. Colorado lists B. elongata broadly. The fact sheet’s inconsistent sepal-count caption is not adopted.
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.
Dmitriy Bochkov · CC BY 4.0
Photo source and identification
Original record · Original image
Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. The selected observation is identified more narrowly as Brassica elongata integrifolia. That source name is preserved rather than silently relabelled as an unspecified subspecies.
iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Dmitriy Bochkov · CC BY 4.0
Photo source and identification
Original record · Original image
Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. The selected observation is identified more narrowly as Brassica elongata integrifolia. That source name is preserved rather than silently relabelled as an unspecified subspecies.
iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Dmitriy Bochkov · CC BY 4.0
Photo source and identification
Original record · Original image
Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. The selected observation is identified more narrowly as Brassica elongata integrifolia. That source name is preserved rather than silently relabelled as an unspecified subspecies.
iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Recognize
An upright mustard with lance-shaped basal leaves, non-clasping upper leaves, yellow four-petaled flowers and slender seedpods. CO-elongated-mustard
Plants & habitat
Spreads by seed along disturbed, rocky and semi-arid ground. Prompt reporting helps prevent establishment. CO-elongated-mustard
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
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. CO-rules-2025
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.
- CO-elongated-mustard — Elongated mustard identification and management, Colorado Department of Agriculture, hosted by Fremont County. Accessed 2026-09-07T01:14:00+00:00. Locator: Identification and impacts; updated July 2015.
- 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.