Bulbous bluegrass
Discuss this plant with the guide — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
Poa bulbosa
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.
Early-season grass spreads by bulbils. Exposure help.
Identification caveat: The USU page has an unrelated heading, but its scientific-name field and grass description identify Poa bulbosa. Only that species-specific body is used.
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.
Stefan.lefnaer · 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. Bulbiferous or viviparous forms are included. A bulbil-producing panicle and swollen shoot bases are different structures; photograph captions distinguish them.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Stefan.lefnaer · 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. Bulbiferous or viviparous forms are included. A bulbil-producing panicle and swollen shoot bases are different structures; photograph captions distinguish them.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Stefan.lefnaer · 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. Bulbiferous or viviparous forms are included. A bulbil-producing panicle and swollen shoot bases are different structures; photograph captions distinguish them.
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 small cool-season perennial with swollen stem bases and purple-green bulbils replacing many flowers in the seedhead. U-bulbous
Plants & habitat
Grows early and becomes dormant as soils dry. It favors disturbed sites; the source does not describe it as equally aggressive in vigorous native vegetation. U-bulbous
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.
- U-bulbous — Bulbous bluegrass, Utah State University Extension. Accessed 2026-09-07T01:16:17+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- 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.