Content tagged with "knapweed"

Cornflower (Bachelor’s Button) (Flowerhead)

Photo of a cornflower, closeup of a flowerhead.
A member of the thistle tribe of composites, cornflower lacks true ray florets; instead, the outer florets of each head have enlarged, flaring corolla tubes that at a glance look something like the strap-shaped extensions of true ray florets. More

Cornflower (Bachelor’s Button; Blue Bottle)

Photo of a cluster of blooming cornflower plants.
A native of Europe, cornflower is a popular garden flower that often escapes to nearby areas. It’s used in bridal bouquets and men’s boutonnieres. Its intense blue color appears in boxes of crayons! More

Cornflower (Bachelor’s Button; Blue Bottle)

Photo of a cornflower, closeup of a flowerhead.
Centaurea cyanus
A native of Europe, cornflower is a popular garden flower that often escapes to nearby areas. It’s used in bridal bouquets and men’s boutonnieres. Its intense blue color appears in boxes of crayons! More

Spotted Knapweed

Photo of spotted knapweed flower head showing spots on involucral bracts
Centaurea stoebe
Spotted knapweed is an invasive plant that outcompetes native communities, takes over pastureland, and even beats back invasive sericea lespedeza! It has arrived in our state. Let’s prevent its spread. More

Spotted Knapweed (Flower)

Photo of spotted knapweed flower head showing spots on involucral bracts
The black, arrow-shaped spot on each bract gives spotted knapweed its common name. More

Spotted Knapweed (Leaves)

Photo of spotted knapweed plant showing foliage and growth habit
A single spotted knapweed plant can have a single stem or as many as 20 stems. It usually flowers in the second year, producing branched stems. The leaves are alternate, deeply lobed, and pale blue-gray. More

Spotted Knapweed Invasive Species Fact Sheet

Use this print-and-carry sheet to identify and control noxious spotted knapweed on your Missouri property. More

Spotted Knapweed Rosette

Photo of spotted knapweed rosette, formed in the first year of growth
By the end of its first year, a knapweed plant is a small basal rosette. It usually bolts in the second year, producing branched stems. More