mesophyte

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A land plant that grows in an environment having a moderate amount of moisture.

from The Century Dictionary.

• noun A plant which is adapted to live under conditiona of medium moisture and dryness; a plant intermediate between the hydrophytes and the xerophytes.
• noun Same as mesophytum.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun botany Any normal terrestrial plant that grows in environments having an average supply of water

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun land plant growing in surroundings having an average supply of water; compare xerophyte and hydrophyte