The Western Flower is a substance mentioned by Bayushi Monban, who noted that while he possessed it, it was insufficient for his needs. He sought a quick method to poison a female target through a servant delivering food to her rooms during the noon meal. Monban indicated that the Western Flower would take too long to be effective.
In a discussion with a Scorpion cousin, Monban reiterated the necessity of a servant to deliver the poison and referred to the Western Flower while seeking more effective ingredients. The Scorpion cousin agreed to assist in acquiring these ingredients, suggesting that the Western Flower was part of a broader plan involving poison.