Tristan is a man from Lyonesse, England then Brittany, France in Mundania. He was mentioned in Up in a Heaval.
Tristan is the son of White Flower and King of Lioness, husband of Iseult of the White Hand, and lover of Iseult the Fair.
Tristan is the namesake of Tristan, the troll.
Human men and women will not have a species in their entries. Also, if the surname of the character is the character's species, it was dropped.
If the character is a child, it will be in the description. The child will more than likely be an adult by this time in the Xanth series.
Many species are single gender, so their entries will not mention it. The species are Fury, Muse, basilisk, cenmaid, cenmare, cockatrice, dryad, maenad, sand witch, sandman, and woodwife. Harpies and nymphs are usually female, and fauns are usually male; but there have been a few exceptions that are noted.
In some instances, I have made educated guesses on gender, species, and some birth years.