Water and polarity
Oxygen attracts shared electrons more strongly than hydrogen does, giving water a partial negative region near oxygen and partial positive regions near hydrogen. Attractions between those regions form hydrogen bonds. These bonds continually form and break in liquid water. Cohesion holds water molecules together; adhesion attracts them to other polar surfaces. A substantial energy input can disrupt many hydrogen bonds before the average molecular speed rises much, giving water high specific heat. Evaporation removes relatively energetic molecules and cools what remains. Ice forms an open hydrogen-bonded arrangement that is less dense than liquid water.
A leaf loses water through stomata. Cohesion helps a continuous water column transmit tension through xylem, while adhesion helps water interact with xylem walls. Neither process means individual water molecules have little suction pumps.
The O–H bonds within a water molecule are polar covalent bonds. Hydrogen bonds are attractions between molecules here. Do not swap them because both names contain hydrogen.