Usage of 'for example' and 'such as'

Do you think that sometimes 'for example' and 'such as' are interchangeable for the same meaning?

1) Wild flowers such as primroses are becoming rare.

2) Wild flowers, such as primroses, are becoming rare.

3) Wild flowers, for example, primroses are becoming rare.

And if you do not mind, is there a meaning difference between #1 and #2? I think that #2 is wrong here. What do you experts think? Thank you so much as usual and have a good and safe day.