|Scientific Name||Rhaponticum repens (Acropiton repens)||USDA PLANTS Symbol||ACRE3|
|Common Name||Russian Knapweed, Hardheads||ITIS Taxonomic Serial No.||780495|
Life zones and habitat: Plains to foothills (3900 to 7500 ft). Disturbed areas, roadsides.
Plant: Colony-forming perennial with multiple leafy branches, 16 to 32 inches tall; foliage covered with fine hairs.
Leaves: Basal and lower stem leaves oblong, 1-3/4 to 6 inches long, often with toothed margins and deciduous by flowering; mid and upper leaves linear to linear-lanceolate or oblong, 3/8 to 2-3/4 inches long, with a sharp-pointed tip.
Inflorescence: Solitary flower heads atop each stem branch are urn-shaped, ~1/2 inch in diameter; silvery buds open to tubular flowers of pink or purple disk florets (no rays) with that turn straw-colored at maturity; protruding white anthers.
Bloom Period: June to September.
References: "Flora of Colorado" by Jennifer Ackerfield, Colorado Department of Agriculture and Invasive Species Compendium.
|BONAP Distribution Map
Map Color Key
© Tom Lebsack 2023
Banner photo: Ten Mile Range and Rhodiola integrifolia (King’s Crown) in Summit County