Siberian elm
Discuss this plant with the guide — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
Ulmus pumila
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.
Numerous seedlings; weak branches. Exposure help.
Identification caveat: Weak-wood descriptions support the structural concern; this guide cannot assess the stability of an individual tree.
Still researching this plant
This is a sourced working profile. Evidence is incomplete for 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.
Shizhao · CC BY-SA 2.5
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. Elms can hybridize and have similar foliage. These are source-identified U. pumila photographs; cultivar identity or hybrid ancestry is not determined.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Melburnian · CC BY 2.5
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. Elms can hybridize and have similar foliage. These are source-identified U. pumila photographs; cultivar identity or hybrid ancestry is not determined.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Dalgial · 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. Elms can hybridize and have similar foliage. These are source-identified U. pumila photographs; cultivar identity or hybrid ancestry is not determined.
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 deciduous tree with small, toothed leaves and round, papery winged fruits in spring. N-ulmus-pumila
Plants & habitat
Abundant seeds create colonies in disturbed ground and grasslands; small seedlings are easier to manage than established trees. N-ulmus-pumila
People
Weak wood and branches are a structural concern. Have a qualified arborist assess large trees near occupied areas. N-ulmus-pumila
Dogs & cats
Falling limbs can endanger animals as well as people; this is a structural-risk inference. Pet ingestion effects are unresolved. N-ulmus-pumila
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-ulmus-pumila — ulmus pumila — 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.