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Wyoming Cooperative Agricultural Pest Survey

Quiz: Noxious Weeds 1

Hover mouse over photo for answer

Field Bindweed

 




Growth Habit: Perennial vine, reproducing from seeds and roots
Leaves: Alternate, simple, arrow-head shaped
Stem: Prostrate, up to 10 ft. long
Flower: Funnel-shaped, pale pink to white
Roots: Creeping Rhizomes, extensive
Seeds: Four per capsule

Photo by: Pedro Tenorio-Lezama, Bugwood.org

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Canada Thistle

 

 

 

Growth Habit: Perennial, up to 4 ft tall 

Leaves: Deeply cut, spiney toothed margins, slightly hairy
Stem: Smooth to slightly hairy, branched at top
Flower: Small, bristly clusters, light lavender to deep rose in color 
Roots: Creeping rootstocks
Seeds: Smooth, light to dark brown

Photo by: Chris Evans, River to River CWMA, Bugwood.org

 

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Leafy Spurge

 

Growth Habit: Perennial, up to 3 ft tall

Leaves: Alternate, long, narrow
Stem: Branched near top, hairless, entire plant contains a milky sap
Flower: Inconspicuous, surrounded by large heart shaped floral leaves
Roots: Brown, numerous, deep spreading
Seeds: Seed can be thrown up to 20 ft by exploding capsule

Photo by: Norman E. Rees, USDA Agr. Research Service - Retired, Bugwood.org

 

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Perennial Sowthistle

 

 

 

 

Growth Habit: Perennial, 4-6 ft tall

Leaves: Alternate, exude milky latex
Stem: Hollow, unbranched except at top
Flower: Yellow, dandelion-like
Roots: Rhizomes
Seeds: Reddish-brown with a tuft of fine white hairs

Photo by: Tom Heutte, USDA Forest Service, Bugwood.org

 

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Quackgrass

 

 

Growth Habit: Erect perennial grass

Leaves: Auricles present, blade soft, flat, may be covered with soft hair
Stem: Culms, 1-3 ft tall, erect, smooth
Flower: Dense terminal spikes 2-6 inches long
Roots: Rhizomes yellowish-white, sharp-pointed, rooting at nodes only
Seeds: Contained in spikelets, awnless or with short straight awns

Photo by: Steve Dewey, Utah State University, Bugwood.org

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Hoary Cress

 

 

 

 

Growth Habit: Perennial herb

Leaves: Alternate, lance-shaped and slightly irregular
Stem: Stoutish, branched toward top
Flower: Small, white,  numerous flower branches
Roots: Extensive horizontally and vertically
Seeds: Reddish-brown

Photo by: Chris Evans, River to River CWMA, Bugwood.org

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Perennial Pepperweed

 

 

 

 

Growth Habit: Erect perennial, numerous stems

Leaves: Alternate, lance shaped
Stem: Smooth, branched, waxy
Flower: Raceme of small white flowers in dense clusters near branch ends
Roots: Deep-seated and spreading
Seeds: Small, rounded

Photo by: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

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Oxeye Daisy

 

 

 

 

Growth Habit: Perennial, up to 2 ft tall

Leaves: Lance-shaped
Stem: Numerous from root crown
Flower: Solitary
Roots: Fibrous
Seeds: Straw-colored

Photo by: Mary Ellen Harte, Bugwood.org

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skeletonweed Bursage

 

 

 

Growth Habit: Perennial, bushy

Leaves: Alternate, undersurface with fine hairs
Stem: Branched, bushy
Flower: Male with clusters of yellow, on solitary, elongated, terminal branches. Female, inconspicuous
Roots: Extensive, creeping
Seeds: Light brown bur with conical spines

Photo by: L.L. Berry, Bugwood.org

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Russian Knapweed

 

 

 

 

Growth Habit: Perennial herb

Leaves: Upper leaves and stem leaves
Stem: Numerous branches
Flower: Single, terminal, lavender, thistle like
Roots: Dark brown to black and heavily scaled
Seeds: Flattened, ivory colored

Photo by: Steve Dewey, Utah State University, Bugwood.org

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Yellow Toadflax

 

 

 

Growth Habit: Perennial, up to 3 ft tall

Leaves: Long, narrow, numerous, smooth, pointed
Stem: Smooth, erect, sometimes branched
Flower: Snapdragon style, with spur, bright yellow
Roots: Woody, vigorous, branched
Seeds: Round

Photo by: Steve Dewey, Utah State University, Bugwood.org

 

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Dalmation Toadflax

 

 

 

Growth Habit: Perennial, up to 3 ft tall

Leaves: Alternate, light green, broad, heart-shaped
Stem: Branching, smooth, leafy
Flower: Snapdragon style, bright yellow, with spur
Roots: Vigorous, deep, extensive
Seeds: Numerous, irregularly shaped

Photo by: Steve Dewey, Utah State University, Bugwood.org

 

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Scotch Thistle

 

 

 

Growth Habit: Biennial, sometimes annual, erect

Leaves: Large, coarsely lobed, hairy, velvety gray appearance
Stem: Erect, branching
Flower: Solitary, terminal, violet to reddish
Roots: Large fleshy taproot
Seeds: Distinctly wrinkled

Photo by: Steve Dewey, Utah State University, Bugwood.org


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