When something is green with plant life it's verdant, a word often used to idealize the countryside with its verdant pastures or verdant hills.
Here's a trick for internalizing verdant's meaning: If you speak Spanish, think of verde — meaning "green." If you speak French, think of vert. Both French and Spanish inherited their words for green from Latin, in which green is viridis. Verdant also can mean grass-colored: "She wore a dress of verdant green."