Verdant Forest?
Verdant is actually a real word. From dictionary.com:
\Ver"dant\, a. [F. verdoyant, p. pr. of verdoyer to be verdant, to grow green, OF. verdoier, verdeier, fr. verd, vert, green, fr. L. viridis green, fr. virere to be green: cf. OF. verdant verdant, L. viridans, p. pr. of viridare to make green. Cf. Farthingale, Verjuice, Vert.]
1. Covered with growing plants or grass; green; fresh; flourishing; as, verdant fields; a verdant lawn.
Let the earth Put forth the verdant grass. --Milton.
2. Unripe in knowledge or judgment; unsophisticated; raw; green; as, a verdant youth. [Colloq.]
I'm only using it for the first definition, obviously.
Verdant Force is referencing the fact that it grows 1/1 Saproling tokens every turn, growing green out of nothing.