Hello.

I would like to know how to list a species complete with an initial prefix. For example, if in the family Araceae one has the genus Philodendron with species hederaceum, how would one go about properly listing them? Would the species have a prefix letter P for Philodendron or A for Araceae? That is, would I write

Araceae
Philodendron
P. hederaceum

or would I write A. hederaceum?

Thank you.