Canada thistle, Cirsium arvense Also known as creeping thistle. Weed identification: Growth form is an erect perennial herb initially with a tap root producing far-creeping white or yellowish rhizome-like roots. Roots can expand laterally more than 5 m and 3 m in...
Jointed goatgrass, Aegilops cylindrica Also known as cylindrical goatgrass. Weed identification: Seedlings have narrow, grass-like leaves with fine hairs on the leaf margins. Mature plants are erect, cool-season annual grasses growing 1-3 feet tall. Stems are hollow...
Russian knapweed, Rhapontocum repens (L.) Also known as Turkestan thistle, creeping knapweed, mountain bluet, Russian cornflower, or hardheads. Weed identification: Russian knapweed is a clonal perennial forb in the Asteraceae (Sunflower) family. It typically forms...
Yellow toadflax, Linaria vulgaris Also known as butter and eggs or wild snapdragon. Weed identification: This weed has been found throughout North America, with a considerable number of cases reported in Colorado, Canada, and the states along the northern border....
Redroot pigweed, Amaranthus retroflexus Also known as redroot amaranth, rough pigweed, common amaranth, or careless weed. Weed identification: Redroot pigweed is a summer annual weed that can reach heights of 0.6 to 1.8 meters. It has a thick and heavily branched stem...