*One of the most invasive species in many western states

*Although not toxic, all knapweeds contain carcinogens

*Wear gloves when handling knapweeds

Toxic to livestock, especially Sheep

*Destructive to land

*Excretes mineral salts making it difficult for other plants to grow

* Has rapid-growing stems, which wind themselves around flowerbeds and borders and quite literally strangle your beloved flowers, veggies or hedge.

*Creates an extensive deep fibrous root system and reproduces and spreads from seed and roots.

*Commonly known as tumbleweed

*Damaging as a seed contaminant, as a forage weed that may contain toxic levels of soluble oxalates and nitrates

*Mature plants break off at ground level, creating spiny, brittle, windblown tumbleweeds

*Easily outcompetes native plants

*Seeds germinate quickly and can lie dormant in the soil for many years

*Sharp burrs cause serious injury to people, pets, wildlife, bicycle and vehicle tires, livestock, and are easily spread by vehicles, people and animals

*Reproduces from seeds, it typically produces around 14,600 seeds per plant

*Seeds are dispersed in the fall when the plant becomes a tumbleweed

*Has a deep taproot and grows 1.6 to 4.9 feet tall

*Toxic to Livestock in large quantities

*Dries out much earlier than native vegetation, significantly lengthening the historic fire season

*Has very fine leaves and stems, which makes it ignite easily and causes fire to spread rapidly

*Plants grow extremely close together as an easily-ignited fuel that quickly burns out of control

*Grows flat and close to the ground and prevents the germination of desirable native species

*Seeds can survive in soil for long periods of time

*2,000 to 10,000 seeds are produced per plant

*Seeds are flung far from the mother plant, easily spreading into new territory

*Stands erect and grows 2 to 5 feet

*Grows in wet areas and is frequently associated with overwatering or standing water in low areas

*Toxic to wildlife in large quantities

*Seed casing enables the seeds to float on water and get caught in wool and animal fur, and this helps the seeds spread to new locations