Hoary cress

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

Lepidium draba

Colorado noxious weed · List B — Stop the spread. CO-rules-2025

Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. Category source · What the lists mean.

Spreading roots; possible livestock poisoning. Exposure help.

Still researching this plant

This is a sourced working profile. Evidence is incomplete for People, Dogs & cats. 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.

**habit** — A dense patch of whitetop in bloom, with broad white flower clusters above green leaves.
Katrin Schneider / korina.info · CC BY-SA 4.0
Photo source and identification
Original record · Original image
Source-identified photograph with visual consistency check Pfeilkresse ( Lepidium draba ) Source labeling and visible consistency checked; not an independent specimen determination.
Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.

**flowers** — Source photographic plate showing a four-petaled white whitetop flower from above and from the side, with a 5 mm scale.
Stefan.lefnaer · CC BY-SA 4.0
Photo source and identification
Original record · Original image
Source-identified photograph with visual consistency check Flower Taxonym: Lepidium draba (subsp. draba) ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Steinberg near Niederhollabrunn, district Korneuburg, Lower Austria - ca. 375 m a.s.l. Habitat: wayside Source labeling and visible consistency checked; not an independent specimen determination.
Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.

**young leaves and buds** — Young whitetop shoot with broad, somewhat toothed leaves around compact green flower buds.
Fabricio Cardenas · CC BY-SA 4.0
Photo source and identification
Original record · Original image
Source-identified photograph with visual consistency check Lepidium draba (brocoli sauvage) dans les environs de Céret. Source labeling and visible consistency checked; not an independent specimen determination.
Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.

Recognize

Blue-green leaves with clasping upper bases and crowded clusters of small white, four-petaled flowers. J-hoary-cress

Plants & habitat

Creeping roots create dense colonies in fields and disturbed ground. Root pieces can regrow after pulling or cultivation. J-hoary-cress

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 county reports possible livestock poisoning and advises against grazing as a simple control method. J-hoary-cress

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.
J-hoary-cress — Hoary Cress, Jefferson County, Colorado. Accessed 2026-09-07T01:08:56+00:00. Locator: Species description and management.
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.