Most invasive species were introduced as ornamental garden plants since they are often quite attractive. Others came as seed unintentionally mixed in with agricultural crops, or on animals brought over from other countries.

What Are the Threats?

The resulting invasion can:

• Have a negative impact on recreation
• Displace native vegetation which reduces forage for wildlife and livestock and damages delicate ecosystems
• Reduce biodiversity including rare and endangered species
• Reduce crop values

Characteristics That Allow Plants to be Invasive

Invasive plants have varying characteristics that permit them to rapidly invade new areas and out-compete native plants for light, water, and nutrients. Some of these characteristics include:

• Early maturation;
• Abundant reproduction by seeds and/or certain plant parts
• Seeds that easily move by way of wind, water or wildlife
• Prickles, spines, thorns, or sap that can cause physical injury and repel animals
• The ability to parasitize other plants
• Production of chemicals that inhibit the growth of other plants(allelopathy)
• High photosynthetic rates