What is a native plant?

Question:

Answer:

A native plant is described as any plant endemic to an area.  What is typically up for interpretation (and what makes the discussion of native plants challenging sometimes) are the boundaries of that area.

Often, the area is defined by political boundaries like state lines, but it can also be defined by boundaries created by geographical features (mountain ranges, rivers, oceans, etc), climatic zones (continental, desert, etc.), ecoregions (grasslands, forests, etc.), and/or soil types (sandy, fertile, etc.), among other things. 

In the United States, native is typically defined as any organism found in that region before European colonization.  The region can be defined by geographic features (east of the Rocky Mountains, east of the Mississippi River, etc.), ecoregions (the Great Plains, the eastern temperate forests, etc.), county or state lines, and/or commonly accepted political regions (the Midwest, New England, etc.).  

Each gardener has their own interpretation of an acceptable region or area that they consider "native."  
The broadest area considered native for many living in Iowa is defined as areas east of the Rocky Mountains within the United States and Canada. This area is primarily grassland or forest with a continental climate. 
The narrowest area considered "native" for those living in Iowa is often defined as a region within the state (i.e., Western Iowa, Central Iowa, Northeast Iowa, etc.), although county is also used as a very specific and small region.