* Dandelion (Taraxacum officinale): Dandelions are common weeds that are native to Europe and Asia. They were introduced to North America in the 1700s and have since spread to almost every part of the continent. Dandelions are prolific seed producers, and their seeds can be easily dispersed by wind, animals, and humans. They can also tolerate a wide range of environmental conditions, making them difficult to control.
* Common reed (Phragmites australis): Common reed is a tall grass that is native to Europe, Asia, and Africa. It was introduced to North America in the 1800s and has since spread to many wetlands, marshes, and estuaries. Common reed can grow up to 15 feet tall and can form dense stands that crowd out native plants. It can also alter water flow patterns and increase flooding.
* Water hyacinth (Eichhornia crassipes): Water hyacinth is a free-floating aquatic plant that is native to South America. It was introduced to the United States in the 1880s and has since spread to many lakes, rivers, and wetlands. Water hyacinth can grow up to 10 feet tall and can form dense mats that cover the water's surface. These mats can block sunlight from reaching underwater plants and animals, and they can also interfere with boat navigation and recreation.
* Lionfish (Pterois volitans): Lionfish are venomous fish that are native to the Indian and Pacific Oceans. They were introduced to the Atlantic Ocean in the 1980s and have since become a major threat to native fish populations. Lionfish are voracious predators and can consume large numbers of small fish, including those that are important to commercial and recreational fisheries. They can also outcompete native predators for food and habitat.