Rush skeletonweed
Alert!
A known population of Rush skeletonweed exists at Heil Valley Ranch (Boulder County Open Space, west of Highway 36). While this population has been managed effectively, the October 2020 Cal-Wood Fire appears to have contributed to its spread. A separate population has also been confirmed in Weld County. Given that the seeds are easily transported by wind, anyone traveling through the foothills north of Boulder or within Weld County should remain vigilant. Please report any immediate sightings to EDDMapS.
(Chondrilla juncea)
Rush skeletonweed is a native of Asia and the Mediterranean region. It is a herbaceous perennial that reproduces by seed and by an extensive root system. The wiry stems of the plant can grow from 1 to 4 feet tall. Stems are hairy from the ground up to 4 to 6 inches high with smooth stems above. These brown hairs are a distinguishing characteristic. Stems and leaves contain a milky latex if cut. The leaves on stems are sharply toothed. The hairless basal leaves are 2 to 5 inches long and 1/2 to 2 inches wide. Flowers are yellow and occur from mid-July to when frost occurs. Flower heads are less than 1 inch in diameter and consist of 9 to 12 flowers, although they may appear to be one. A vigorous mature plant can produce up to 1,500 flowers capable of distributing 20,000 seeds. Plants usually overwinter as rosettes which closely resemble common dandelion.
Watch aerial treatment video as a helicopter pilot uses GIS tracking software to treat rush skeletonweed at Heil Valley Ranch in Boulder County, Colorado.
Watch aerial treatment landing video as a helicopter pilot lands for a refill of herbicide.
