Packera glabella (formerly Senecio glabellus) is one of several plants with the common name butterweed, this one has also been called cressleaf groundsel and yellowtop. It is native to central and southeastern North America but spreads so aggressively, overtaking other native plants, that it is considered[by whom?] invasive. Further, when eaten, it is toxic to humans and highly toxic to horses & cattle. Authorities[who?] recommend eradicating it, conventionally with 2,4-D (which dissipates completely from the soil within 2 weeks).[5]
Packera glabella involucres
Distribution
Butterweed is found from Texas north to South Dakota and east to Ohio with a disjunct population in Delaware. It grows in clay and loam soils in disturbed areas and in prairie and floodplain habitats.
NatureServe lists Packera glabella as Secure (G5) worldwide and Critically Imperiled (S1) in Nebraska, Imperiled (S2) in Kansas, and Vulnerable (S3) in North Carolina.[2]
