The oleander was said to be a blessed flower once instead of the poisonous thing that it is now. The oleander would be given to children in the hopes it would distill long life and prosperity.
The day the oleander became poisonous was the day the Tabula Rasa took place.
The Tabula Rasa, or slate wiping, was a great culling of the western provinces.
To prevent uprising, the knights of the eastern cities joined together and exterminated the people of the western province.
When the blood of the citizens seeped into the dirt where the oleander bloomed, the flowers grew twisted and strange inside, but their blossoms still looked beautiful.
The knights brought home baskets of oleander flowers in celebration.
The royal family held a party that night and cooked all of the oleander flowers into tea, for they had heard it was delicious. Much to their surprise, however, they quickly became sick.
The oleander had betrayed them, just as they had betrayed their people. The Tabula Rasa had extended beyond just those of the western provinces, and the whole country was wiped clean.