Perennial Cornflower
Centaurea montana
Washington State Classification
Monitor List
This plant is on the monitor list - it is not a listed noxious weed in Washington.
Quick Reference
Identification
Growth Habit
Perennial cornflower is a hairy perennial plant that spreads by creeping rhizomes. Plant grow up to 2-2.5 feet tall (60-80 cm).
Leaves
Leaves typically simple, with smooth margins and decurrent (leaf blade extending down along the stem)--forming wings on stem. Leaves lance-shaped to egg-shaped, thinly hairy to woollly, and 4-12 inches (10-30 cm) long. Lower leaves sometimes remotely dentate (toothed) to lobed along the edges.
Flowers
Flowerheads solitary at stem tips (to rarely few). Bracts at the base of the flowerhead overlap like shingles (imbricate), with blackish-brown tips that are deeply toothed. Blooming flowerhead around 2 inches wide, inner flowers are violet while outer flowers are blue, enlarged and extending outward.
Fruit & Seeds
Seeds (cypselae) are brown, 5-6 mm long and have soft, appressed hairs. Each one has bristles on one end (a pappus) that are 0.5-1.5mm long.
Impact
This plant is on the monitor list - it is not a listed noxious weed in Washington. Please contact Adam Pfleeger at adam.pfleeger@co.chelan.wa.us to report locations or for more information.
Ecology & Spread
Habitat
Grown as an ornamental, perennial cornflower can escape and grow in a variety of habitats including roadsides, woodlands, and sagebrush scrub.
Spread Mechanisms
Reproduction
Plants spread by seed and vegetatively by rhizomes.
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