Field scabiosa
(Knautia arvensis)
Herbaceous perennial in the teasel family, this species grows 1-3 feet tall. Plants are erect, hairy and sparsely branched with bluish/purplish flowers and deeply cut leaves.
Other names for this plant include:
- Common names: blue buttons, meadow widow flower and gypsy's rose
- Scientific names: Scabiosa arvensis
Classification in Wisconsin: Restricted
- Ecological Threat
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- Invaders of prairies and grasslands threaten Wisconsin's most poor vegetation community, the tallgrass prairies.
- This species is also commonly found along roadsides and disturbed areas.
- A single plant can produce up to 2,000 seeds.
- Deep taproots make this species very difficult to remove.
- Infestations also significantly decline hay production and pasture land-carrying capacities.
- Identification
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Leaves & stems: Stems have stiff hairs angled downwards but are not prickly. Leaves are hairy. Lower leaves are usually coarsely toothed, or sometimes entire, and form a basal rosette. The upper leaves are opposite and deeply, pinnately cut.
Flowers: Blue to purple. The inflorescence is a dense composite of small florets clustered into a domed-shaped head resembling a single flower that occurs singly at the ends of stems. Below the flower head is a ring of narrow green bracts. Plants bloom June-September.
Fruits & seeds: The fruit is nut-like, cylindrical, small, and hairy.
Roots: Plants develop a deep taproot.
- Control
- Mechanical:
- Cut or mow plants before they set seed to prevent the establishment of new plants.
- Pulling is seldom effective due to the difficulty in removing the long, branched roots.
- Infestations can be controlled by tilling and cultivation of other species. Heavily infested pastures/hayfields can be cultivated and rotated to an annual crop.
- Escort (metsulfuron-methyl) at 20 gr/ha (8.0 gr/acre) provides excellent control. The escort should be applied to actively growing plants up to the early flower bud stage.
- Resources
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