This story arose prior to the Spaniards' arrival on the American continent, during the Inca Empire:
In order to explore and become acquainted with his domains, the highest Inca authority ordered expeditions to seek out new culinary ingredients.
One day, the Inca (as they called the king then) sent for Apu, the bravest and most loyal warrior in his army. The Inca told him that a plant with stickers was found during the expeditions that caused a terrible pain upon contact, and besides, they were protected by an enormous serpent that attacked anyone who dared to approach... "and only one of the chaskis survived such an encounter." Then Apu replied, very sure of himself, "I will destoy that monster and avenge the death of my brothers."
Apu worked out a plan and sent the most nimble warrior to bring the enormous serpent to a bonfire that was prepared by the members of the army.
Once there, a puff from the shrewd serpent thwarted the plan. Then it spit its venom at Apu, who immediately passed out. That was when Chunta, the strongest warrior, grasped the serpent by its belly and threw it at the cactus. As it tried to escape the enormous serpent got tangled in the thorny plant and met its death.
The warriors took the head of the serpent to the Inca to calm the population and brought along a segment from the plant that saved them from death. It did not take long for the plant to spread throughout the kingdom to provide its delicious fruit for everyone.