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Photo	Common Name Botanical Name	Family	Reason for Concern
	Bull Thistle Cirsium vulgare	Sunflower	Aggressive   • Forms monoculture   • Spiny   • Unpalatable to livestock
	Yellow Starthistle Centaurea solstitialis	Sunflower	Very aggressive   • Extreme genetic adaptability   • Invades disturbed areas and dry rangeland   • Toxic to horses in large quantities   • Armed with spines
	Spotted Knapweed Centaurea maculosa	Sunflower	Aggressive   • Grows in disturbed areas and in dry to moist rangelands   • Releases chemical substance to inhibit growth of vegetation competition
	Medusahead Taeniatherum caput-medusae	Grass	Extremely competitive   • Crowds out desirable and native plants   • Grazing capacity reduced up to 75%   • Introduces fire into non-fire prone ecosystems
	Dalmatian Toadflax Linaria dalmatica	Figwort	Aggressive   • Invades native plant communities on roadsides and rangeland   • Unpalatable to most herbivores
	Klamathweed Hypericum perforatum	St. Johnswort	Toxic   • Usually in sandy or dry soils along roadsides   • Contains a toxic substance that causes grazing animals to lose weight & develop skin irritation in strong sunlight
	Purple Loosestrife Lythrum salicaria	Loosestrife	Extreme Competition   • Infests creeks and wetlands chokes waterways,crowds out native vegetation   • Displaces native fish and wildlife   • Perennial
	Scotch Broom Cytisus scoparius	Pea	Spreads Easily   • Invades oak woodlands, foothills   • Invades dry riverbeds and other waterways
	Tree of Heaven Ailanthus altissima	Quassia	Aggressive Competitor   • Invades riparian areas   • Rapid growth, primarily in disturbed areas   • Persistent stump and root sprouter
	Butterfly Bush Buddleia davidii	Buddlejaceae	Exotic Invader
	Giant Reed Arundo donax	Grass	Aggressive Invades riparian areas
	Squarerose Knapweed Centaurea virgata var. squarrosa	Sunflower	Aggressive   • Grows in dry, disturbed areas   • Replaces native vegetation on rangeland creating multi-acre monoculture
	Scotch Thistle Onopordum acanthium	Sunflower	Very aggressive   • Invades most habitats forming dense, impenetrable patches   • Unpalatable
	Puncturevine Tribulus terrestris	Caltrop	Toxic   • Grows in most habitats   • Can be toxic to livestock   • Hard, spiny burs damage wool   • Injurious to feet of livestock, humans, & animals
	Perennial Pepperweed Lepidium latifolium	Mustard	Extremely Competitive   • Out-competes native vegetation   • Mechanical removal spreads plant
	Himalayan Blackberry Rubus discolor	Rose	Aggressive   • Invades riparian areas   • Invades marshes, oak woodlands   • Smothers competition and forms low productive monocultures