hygro-, hygr- +

(Greek: moist, moisture, wet, damp)

hygrotropic
A reference to movement in response to humidity or moisture.
hygrotropism
Orientation, or movement, in response to humidity or moisture.
panhygrous (adjective), more panhygrous, most panhygrous
Relating to being moist all over or wet in all parts.
stenohygric
Organisms adaptable to a narrow variation in atmospheric humidity.
substratohygrophile
A reference to an organism that thrives in moist substrata.
substratohygrophilous
In biology, thriving on moist substrata or sediment (subsoil), or the medium to which an organism is attached or upon which it grows.

Cross references of word families that refer to "water": aqua-; hydat-; hydro-.