The Viridians are (or were) a green-skinned human subspecies descended from the gods of the Uttermost War, the Wild Men of the Confederate Tribes, and most notably the mer-people of the Trident Gulf. Viridumar was founded by the Viridians in 101 BCCC and they have traditionally ruled the city and the empire that it grew into ever since, even as the population of the city has swelled with humans of other lineage. Due to inbreeding, internal strife, and low fertility, the Viridians have dwindled over the years until the current Emperor Hautulin Seheitt is the only pure-blooded Viridian left. Many of the upper ranks of the nobility claim some trace of Viridian blood but their claims are dubious and self-justifying at best.
In recent times, as the Viridan race has been all but forgotten, common usage has changed such that to most people, a “Viridian” is any citizen of Viridstan and/or Viridumar, and those who still care about such things must clarify that the Emperor and his relatives are (or were) “True Viridians”. However, the nobility (and especially the Emperor) can be quite prickly about this, and referring to a commoner as a “Viridian” in the Emperor’s presence is likely to be met with retribution.