What does "add one " mean?!

It used to say "one mana of any colour", I infer not deleting "one" is just a typo.

Two mana plus a creature is probably about right for a two-mana boost, but I'm not sure when I'd actually want to play this: I feel like I'd usually just rather have a mana creature or a landsearch spell, and be frustrated if I have this, but sometimes it will make an interesting combo.

Aww, and here I was hopping you had a , so you could put it into or but not or .

Silly aside; it aint a great enchantment, but it aint bad either. It has the advantage of being castable even if you only found one forest and a manaelf; most of the 'get two extra mana' things need 3 mana. So yes, this certainly has a niche and I think would need to be watched like a hawk in case it got too good. But even if it is good, a lightning bolt will usually get rid of it, so I'd guess it's just niche.

I guess this is very good on creatures. Infinite mana with Pili-Pala, or with Leech Bonder or Puresight Merrow plus a mana-washer.

I agree this is a different enough tweak on Overgrowth / Greenweaver Druid that it has a role.

Ideally, you want this on one casting cost etb trigger creatures. There aren't many of those, it's true. But I could see someone go: Round 1 - Elvish Pioneer. Round 2 - Land drop, Cast this, tap Pioneers, cast a 3cc creature, because, you know, why not? I got the up. Get ready to cast a Titan next turn.

I do love this with creatures. Gilder Bairn is a fan.