My father uses our small backyard to plant some vegetables and tea. We have a fence that houses some climbing trees.
One of the climbing trees bore these strange (to us) fruits. I would appreciate if someone could identify it.
Photo of the young fruit, which is a pale green-yellow color and lumpy:
Photo of the small yellow flower:
Photo of the tree:
More information: We are in South Brazil. People give him seeds and seedling or he brings them from the wild, so we do not remember the origin. The fence once had a passion-fruit (Maracuja) that grew in a similar fashion. It's summer in the time of the photos (same day of the question), the fruits are still young and not mature.