This is the problem of using what are known as ‘common names’ for plants. There can be many names for the same plant and if you are talking to someone in another country about a ‘corn poppy’, they won’t know what you mean.
Have a look at some plant names in books or plant lists on the internet, such as garden centre or plant nursery websites, and see if you can tell the difference between common names and botanical names.
For example: