Final answer:
The coconut is an example of a plant that produces a seed capable of water dispersal which also transports its own water, allowing it to float to new locations for germination. This adaptability is part of the reason seed plants can thrive in a variety of environments, even arid ones.
Step-by-step explanation:
A plant that produces an ocean-going seed that transports its own water is the coconut. The coconut has a tough, buoyant exterior which allows it to float in the ocean over long distances, potentially dispersing the seed to new locations where it can germinate. This special adaptation is vital for the coconut as it enables the species to colonize new areas, especially on tropical shorelines. This is an incredible evolutionary strategy as coconuts can travel long distances due to their floatation ability and water storage capacity.
While coconut seeds are adapted to water dispersal, it's interesting to note that seed plants have largely evolved beyond needing water for reproduction. Developments like pollen and seeds have allowed these plants to thrive in various, especially dry, environments. Pollen enables the transport of male gametes without water, and seeds provide protection and nourishment for the embryo, allowing plants to reproduce successfully in arid climates.