Cressleaf Groundsel, commonly referred to as Butterweed, may look beautiful.
But it is a weed and can be toxic to livestock if it is present in hay.
On a recent trip to a medical office, I noticed a ‘beautiful’ yellow flowering plant that was frankly striking.
On closer inspection and with some research, I learned the plant is Cressleaf Groundsel, Packera glabella, formerly Senecio glabellus, is a nasty weed. Since it is a winter annual, it is in flower now.
From afar, it might look like sunflower, but it does not flower this time of year.
Sunflower is in flower typically late August.
The following paragraph is from an OSU Fact Sheet:
Cressleaf groundsel is toxic to livestock when present in forage grazing systems, or in stored feeds (e.g., dry hay or ensiled forages). Harvesting and drying the forage does not eliminate the threat to livestock. Cressleaf groundsel produces pyrrolizidine alkaloids, secondary metabolites that produce a toxic compound that negatively impacts liver function, resulting in liver disease via necrosis. When assessing poisoned livestock, clinical symptoms may include, but are not limited to:
- lack of appetite
- loose stool
- anorexia
- incoordination
- sensitivity to light (in severe cases)
(Bildfell, 2024).
Consumption of cressleaf groundsel has also been linked to abortions in grazing livestock, specifically cattle.
This information is from: https://cfaes.osu.edu/fact-sheet/cressleaf-groundsel-identification-and-control
The above fact sheet also contains control measures.
Once this weed gets established, it can really take over a field.
Another post by Joe Boggs about Groundsel- Cressleaf Groundsel: A Grown-up "Weed" contains additional images:
Although beautiful,
this weed can become a big problem.
