Sonchus arvensis var. glabrescens   field or perennial sow-thistle
           (Alt: Sonchus arvensis ssp. uliginosus )
Asteraceae (Alt: Compositae )
invasive                      herbaceous           Greenbelt

UW Burke Herbarium Link: Sonchus arvensis var. glabrescens
USDA Plants Link: Sonchus arvensis var. glabrescens   (SOARU)