Importar works like gustar. In fact you can say that
importar : gustar :: to care : to like
That is, importar relates to gustar in more or less the same way as English "to care" relates to "to like" (grammatically speaking).
It's not a reflexive (pronominal) verb. It has two arguments: the person who cares about something, and the thing that someone cares about. The thing is the grammatical subject, but it tends to be found after the verb, instead of before as usual. The person is an indirect object, or dative, and it tends to be before the verb instead of after. So the usual word is reversed (again, exactly as in gustar).
I guess that your example
Usted/importar/todas/el/especies en peligro
is supposed to mean "you (formal) care about all the endangered species". In that case the correct sentence in Spanish would be
A usted le importan todas las especies en peligro.
A usted and le refer to the same person, but this redundancy is grammatically compulsory in this case. Note that usted is a second person pronoun but it works like third person, therefore we use le, not te, to refer to it.
Importan is in the plural (-n) because the grammatical subject is todas las especies en peligro, which is plural. Don't let the unusual order fool you.
If you need to "translate" this into English, you could think of importar as equivalent to "to be important":
A usted le importan todas las especies en peligro.
"To you are important all the endangered species."