Jacobaea Species, Common Ragwort, Stinking Willie, Tansy Ragwort

Native to Europe, known as common ragwort there. Produces huge numbers of seeds carried by air, can be a very rampant invader of waste gr...Read Moreound, meadows etc having the ability to almost completely take over large tracts of land. thrives on various soil types including dry areas with poor soil. A bit sporadic in where it occurs though, being dependent on the wind to disperse seeds.
Poisonous to horses and cattle, less so to sheep which may eat it.
A favourite food of the Cinnabar moth.
The term 'tansy ragwort' is incorrect and causes confusion, Tansy is a separate species entirely though there is a slight resemblance between the two species, both having bright yellow flowers. 'Ragwort' or 'common Ragwort' is the proper name for this species.

I want to say something in the defense of this beautiful wildflower. In the right place it is a very valuable plant, a very rich nectar ...Read Moresource for hoverflies, bees, butterflies, moths etc..

It is a noxious weed but it is a great plant for butterflies and bees. If you have a wildflower garden, then I would not be against grow...Read Moreing this plant. Cut the heads off as soon as the flowers have passed and you will prevent their self-seeding everywhere. This plant only reproduced by seed, not by rhizomes.

Colorado Class A Noxious Weed. Mandatory eradication.
All locations of this plant in Colorado should be immediately reported to th...Read Moree Colorado Department of Agriculture.