Answer:
Water has a high Cohesion because of Hydrogen bonding. This is important as transport of water in the Xylem in plants relies on water being pulled up. Cohesion also gives the water a high surface tension, allowing small organisms, such as Pond Skaters, to walk along it.
Step-by-step explanation:
Water molecules forming hydrogen bonds with one another. The partial negative charge on the O of one molecule can form a hydrogen bond with the partial positive charge on the hydrogens of other molecules. Water molecules are also attracted to other polar molecules and to ions.
Plants obtain the hydrogen they need from water molecules. Don't try to feed your plant hydrogen gas -- your plant wouldn't know what to do with it if you did. As long as they have water, plants can readily obtain all the hydrogen they need. :)