What Makes a Plant Invasive? Understanding Terminology

This blog was written by Anelise Bullard, UF/IFAS CAIP communications intern.

Side by side image of fragrant waterlily and arrowhead vine
Fragrant waterlily (Nymphaea odorata) a native aquatic plant (pictured left) and arrowhead vine (Syngonium podophyllum) a nonnative (pictured right).

When you hear the term “invasive plant”, what’s the first thing that comes to mind? You may think of water hyacinth (Eichhornia crassipes) and cogongrass (Imperata cylindrica), or maybe you simply think of something that has moved to a place it doesn’t belong. We can dig deeper and wonder, “What exactly makes a plant invasive?” In this blog, we will talk about some terminology that ultimately categorizes a plant as “invasive.” 

The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Invasive Species Council (ISC) defines an invasive species as meeting three criteria: the species is nonnative to a specific area, was introduced by humans, and does or can cause harm to the environment, economy, or humans. All invasive species start out as nonnative species, meaning that they don’t occur naturally in a geographic area. Once they are introduced, it may take some time for a nonnative species to become invasive, if they ever do. This is called a lag phase; you can learn more about it by reading our previous blog. Below, we’ll define these classifications and go more in depth about what they mean for plants.

 

Cattail
Cattail (Typha sp.) can be a nuisance plant depending on the situation.

Invasion Terminology & Categories

Native – A species that occurs naturally in a specified geographic area.  

Nonnative – A species that does not occur naturally in a specified geographic area.

Nuisance – An individual or group of species that causes management issues or property damage, presents a threat to public safety, or is an annoyance. This can apply to both native and nonnative species. Cattails (Typha sp.) are aquatic plants native to Florida that, when unmanaged, can grow out of control and become a nuisance.

Noxious – Any plant or plant product that can cause damage to crops, livestock, irrigation, navigation, natural resources, public health, or the environment. Coral ardisia (Ardisia crenata) is toxic to livestock, earning it the title of a noxious weed. 

Prohibited – A species determined injurious to humans. When a plant is prohibited, its sale and distribution is strictly limited. Giant salvinia (Salvinia molesta) grows rapidly and can cover entire stream and lake surfaces. These dense growths can impede boating, fishing, and swimming, and can clog water intakes for irrigation and electricity generation. 

After reading this blog, I hope you have a better understanding of some invasion science terminology and what categorizes a plant as “invasive”. While there are many more terms and ideas involved in the field, these are a few of the basics that create a foundation for becoming more knowledgeable about invaders. The definitions in this blog are cited from the AskIFAS article on “Standardized Invasive Species Terminology for Effective Outreach Education”. You can find our Invasive Species Terminology one-pager and many more resources on our website! 

Coral ardisia (Ardisia crenata) is a noxious plant (pictures left) and giant salvinia (Salvinia molesta) is a prohibited species (pictured right).

 

 

 

 

 

 

 

 

 


If you have any questions, please email us at caip@ifas.ufl.edu.

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Christine Krebs, Communications Manager for the University of Florida Institute of Food and Agricultural Sciences Center for Aquatic and Invasive Plants (UF/IFAS CAIP).
Posted: June 28, 2024


Category: Blog Community, Home Landscapes, Invasive Species, Natural Resources, UF/IFAS, UF/IFAS, UF/IFAS Extension, UF/IFAS Extension



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