Common Name: Field Scabious
Scientific Name: Knautia arvensis
Habitat: roadsides, grassland, grassland dry, grassland wet, disturbed areas, farmland
Provincial Designation: Noxious
Noxious weeds are plant species designated in the Alberta Weed Control Act. Noxious weeds must be controlled, meaning their growth or spread needs to be prevented.
Field scabious is native to Europe and was introduced to North America as an ornamental garden plant.
This weed can quickly establish along roadsides, open grasslands, pastures and rangeland. Infestations can reduce pasture productivity.
The flowers of field scabious are blue or purple in colour. What appears to be one flower is actually a composite of many small flowers that are clustered together into a single flower head. Each of these single small flowers has united petals with four lobes. Flower heads are 4 cm wide and sit on the end of stems.
The hairy leaves are variably lobed and oppositely arranged along the stem. Stems are erect, hairy, sparsely branched, and grow up to 1.5 m tall.
Seed head is a bristly green dome on a ring of pointy green sepals (small leaves immediately below the petals on the flower head).
Can Be Confused With ...
Wild Bergamot - Monarda fistulosa - a native species, which has unlobed leaves with serrated edges and flowers are more tubular in shape.
Pincushion flower - Scabiosa genus - which is an ornamental garden plant and fine for you to grow!
Learn more about this species:
See Fact Sheet - Alberta Invasive Species Council