Noxious Weed Identification

Identification & Control

Colorado is seeing a dramatic increase in noxious weeds. Left uncontrolled, noxious weeds will form dense mono-cultures and displace native and desirable plants. Native plant loss affects wildlife that depends on the native vegetation for survival.

Please select from the following to find detailed information on the weed in which you’re interested.

Plants A - C


arundo habit

Black Henbane

black henbane - small plant


Bouncingbet - white

Bull Thistle

bull thistle flower

Canada Thistle

canada thistle flower


cheatgrass plant


chicory flower

Chinese Clematis

chinese clematis seed

Common Mullein

common mullein rosette

Common Tansy

common tansy flower

Cypress Spurge

cypress spurge

Plants D - K

Dalmatian Toadflax

dalmatian toadflax flower

Dames Rocket

dames rocket flower

Diffuse Knapweed

diffuse knapweed seedhead

Dyer's Woad

dyers woad seed

Field Bindweed

field bindweed flower

Hairy Willow-Herb

hairy willow herb flower

Hoary Cress

hoary cress plant


houndstongue seed


knotweed plant

Plants L - R

Leafy Spurge

leafy spurge flower

Moth Mullein

Moth Mullein flower

Musk Thistle

musk thistle multiple flowers

Myrtle Spurge

myrtle spurge flower

Orange Hawkweed

orange hawkweed flower

Oxeye Daisy

oxeye daisy flower

Perennial Pepperweed

perennial pepperweed flower

Plumeless Thistle

plumeless thistle flower

Poison Hemlock

poison hemlock flowers

Purple Loosestrife

purple loosestrife flower

Russian Knapweed

russian knapweed flower

Russian Olive

russian olive fruit

Plants S - Z

Saltcedar - Tamarisk

salt cedar flower

Scentless Chamomile

chamomile flower

Scotch Thistle

scotch thistle plant

Spotted Knapweed

spotted knapweed flower close up

Sulfur Cinquefoil

sulfur cinquefoil flower


teasel seedhead

Yellow Starthistle

yellow starthistle flower

Yellow Toadflax

yellow toadflax plant