Efflorescence

Efflorescence is a Commander card through and through — the incremental value of untapping a land each turn compounds over a long game in ways that simply don't matter in faster formats. In Legacy, Modern, and Pioneer, three mana for an enchantment that does nothing the turn it enters is unplayable; the formats move too fast and the card generates no immediate board presence. Pauper is the one non-Commander format where cheap engines occasionally find homes, but Efflorescence competes poorly there too, since green already has better mana acceleration at common. In Commander, it earns its slot in any deck where Dryad of the Ilysian Grove or Chromatic Lantern is making all your lands basic-typed, or in mono-green and Selesnya builds where the trigger fires naturally every single turn.