It is well known that every primitive word in a rank two free group is conjugate to either a palindrome or the product of two palindromes. We present an enumeration scheme that gives each primitive as the unique palindrome in its conjugacy class or as a product of two unique palindromes that have already appeared in the enumeration scheme.  We use this result to obtain some necessary and sucient geometric discreteness conditions in PSL(2;C) (equivalently Isom+(H3)). This is joint work with L. Keen.