What are some limitations of a dichotomous key?

1.It is only useful when the organism that is being identified was or is a part of organisms that are part of the key. An organisms is usually misidentified if it does not belong to the key.  

2.It’s a complex mechanism of organism identification and may leads to chain of worng interpretations.  

3.The characteristics which are devised to identify an organism might not be a distinct feature of the species already exiting in the dichotomous key.

4.Dependency on physical characteristics, does not take into account genetic characteristics

"a.) well–developed vascular system."