This page is devoted to alerting our members to new sightings of uncommon weeds. Since 2004, CWMA has worked to provide a way for our members to receive up-to-date information about new infestations of high priority and unknown noxious weeds.
To Report a Sighting
Download the form HERE
Complete it and send it to us. We will share the information with CDA-EDDR and with the local county/city weed manager.
Once the sighting is verified we may post it on our site. Be sure to take picture!
Rush Skeletonweed (Chondrilla juncea)
Rush Skeletonweed was found on July 19th by Boulder County Parks and Open Space staff and verified by CDA. It was found about 6 miles North of Boulder along Hwy. 36 on Boulder County open space property.
Arundo (Arundo donax)
A single clump of plants were found in Jefferson County by Alicia Doran. Other possible sightings have been reported from Denver and in the southern part of the state.
Arundo is a highly invasive grass-like plant that likes streambanks. It can grow 15+ feet tall and has a hollow stem.
photos by Alicia Doran
Yellow Starthistle (Centaurea solstitialis)
A new site was reported to the CDA-EDRR Specialist just outside of Beulah (Southwest of Pueblo) in Pueblo County on private land. The estimated acreage is 40 acres with approximately 20% infested with Yellow starthistle.
photos by CDA-EDRR
Reported to the CDA-EDRR Specialist by Nan Lederer of the CU Herbarium. This infestation is located northeast of Trinidad in Las Animas County on the County Road 95 right-of-way. Plants extended along the road for approximately 200 yards.
photos by Jim Walker
Swainsonpea (Sphaerophysa salsula)
Mark Sweppenheiser of Jefferson County Weed and Pest discovered Swainsonpea near Morrison.
For more info
photos by Alicia Doran
Yellow Flag Iris (Iris pseudacorus)
Ray Sperger, owner of Ark Ecological Services, LLC has reported Yellow flag iris. It was spotted along the edge of a pond in Loveland. Other sightings include Boulder County.
This non-native plant is listed as a noxious weed in a number of other states. It can quickly form a monoculture along the edge of wetlands.. INFO - http://dnr.metrokc.gov/wlr/lands/weeds/iris.htm
top photo: Ray Sperger
lower photo: King County WA Noxious Weed Control Program
Narrow-leaved Dalmatian toadflax (Linaria genistifolia)
Paul Burgell of Rio Blanco County reported 5 acres of narrow-leaved Dalmatian toadflax found on private property in Loma which is just over the county line in Garfield County.
INFO - www.ext.colostate.edu/PUBS/NATRES/03114.pdf
Image - www.s-weeds.net/familjer/tubiflorae/scrophulariaceae/linariagen.html
Common tansy (Tanacetum vulgare)
Denny Bohon, USFS, spotted common tansy growing on private property west of West Creek along CR 68.
INFO - usda plants database
photo: www.mda.state.mn.us/.../ common_tansy.htm