Answer:
The system of veins on a leaf on plant are similar to , the system of streams and rivers on earth's terrestrial landscape - in that both systems are used to move fluid (water) filled with nutrients away from their sources.
However, the system of veins on a leaf are much more capable and actually do move nutrient rich fluid in both a positive and negative flow in direction. But, the systems of streams and rivers on earth's landscape, are naturally dependent on gravity and declining slope of landscapes' for a negative flow in direction.
Explanation:
Leaves on a tree are a more enclosed or self contained system that can move fluids against the force of gravity through osmotic forces and physical characteristics provided by leaf and the attached plants physiology.