Major Rangeland Plants of Idaho: Noxious Weeds

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Major Rangeland Plants of Idaho Noxious Weeds
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Dyers Woad

• Perennial
• Introduced
• Poor for Grazers
• Poor for Browsers

Flat topped seedhead
Hanging clusters of green pods (dark brown to
purple on maturity)
Lanceolate leaves clasp at stem
Idaho Weed Resources. http//www.uidaho.edu/weeds
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Hoary Cress/Whitetop

• Perennial
• Introduced
• Poor for Grazers
• Poor for Browsers

Terminal flowers
Herbaceous (forb)
Idaho Weed Resources. http//www.uidaho.edu/weeds
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Leafy Spurge

• Perennial
• Introduced
• Fair for Grazers
• Poor for Browsers

No flower petals yellow bracts below flower
Rhizomatous roots
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Poison Hemlock

• Perennial
• Introduced
• Poor for Grazers
• Poor for Browsers

Flowers arranged in umbel
Leaves highly divided carrot-like
Poisonous This plant can contains a toxic
alkaloid
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Rush Skeletonweed

• Perennial
• Introduced
• Fair for Grazers
• Fair for Browsers

Yellow flowers
linear leaves on stem or dandelion-like leaves in
rosette
Idaho Weed Resources. http//www.uidaho.edu/weeds
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Spotted Knapweed

• Perennial
• Introduced
• Fair for Grazers
• Poor for Browsers

Flower head characterized by dark-tipped bracts
Pinkish-purple flowers
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Yellow Starthistle

• Annual
• Introduced
• Poor for Grazers
• Poor for Browsers

Star-like spines at base of flower
Taproot