Answer:
What has 13 hearts but none beat?
What must be in the oven yet can not be baked? Grows in the heat yet shuns the light of day? What sinks in water but rises with air? Looks like skin but is fine as hair?
What does everyone know how to open but not how to close?
What breaks on the water but never on the land?
Two brothers we are, great burdens we bear. All day we are bitterly pressed. Yet this I will say, we are full all the day, and empty when go to rest.
It produces a flower but it is not its fruitΝΎ it produces branches which are its fruit.