Actually, that's a long story. You see, this particular female Yoshi had been friends with a polite shyguy named Shiloh. Shiloh and Yoshi had been inseparable, until Shiloh heard a rumor that Yoshi had a crush on him. This made Shiloh uncomfortable until he finally said to Yoshi, "I'm sorry, but we just can't be friends anymore, Yoshi." This made Yoshi very upset, and she was angered by Shiloh's sudden rejection of their friendship. However, instead of crushing the flowers in Shiloh's garden, Yoshi searched for the answer to why Shiloh didn't want to be friends with her anymore. She soon found out that there had been a spreading rumor that she had a crush on Shiloh, which was not true. She confronted Shiloh and told him about the rumor that was'nt true and that she wanted to be merely his friend. Shiloh accepted their reconstructed friendship, and when Yoshi excitedly told her mother about it, Yoshi's mother said, "The flower of gossip, while seems pretty, is a deceiving monster, and should be taken care of with a foot's underside." Yoshi thought her mother's choice of words were peculiar, but they rang through nevertheless. So Yoshi never spread rumors or believed things from secondary sources. So "Yoshi stepping on a pretty flower" is really a symbol of Yoshi's disdain for rumors.
So, What's in YOUR wallet?