Noxious Weeds

The Colorado Department of Agriculture and Boulder County have identified invasive, noxious weeds that pose an economic and environmental threat to our State.

In accordance with the Lyons Municipal Code (Sec. 7-5-30), it is unlawful for any any owner, lessee, agent, occupant or person in possession or control of any lot or tract of land to allow any brush, weeds, local noxious weed or state noxious weed. 
As such, it is the noted individual's responsibility to eliminate noxious weeds. 
Noxious weeds are defined by State and Federal law as non-native planets that have no natural controls, and are able to adapt to varied conditions. The Colorado Weed Act places these weeds into three separate lists:

List A weeds
: Elimination required
List B weeds: Management required
List C weeds: Management recommended

Boulder County's Noxious Weed List

List A

Myrtle Spurge

Myrtle spurge is a tap rooted perennial that can reproduce by seed or plant fragments. Myrtle spurge is an escaped ornamental, found in small patches. This plant contains a toxic, milky sap which can cause severe skin irritations, including blistering. Myrtle spurge is poisonous if ingested; causing nausea, vomiting and diarrhea.  Wearing gloves, long sleeves, shoes, and eye protection is highly recommended when in contact with all plant parts.

Read more on Myrtle spurge identification and management
Myrtle Spurge 3
Myrtle Spurge 2
Myrtle Spurge 1

Identify and Mitigate

To help Identify these and other species, download the Colorado Department of Agriculture’s Colorado Noxious Weeds Mobile App for iOS and Android.
For more information on ways to mitigate these and other invasive species can be found on the Colorado Department of Agriculture website at