(Elfhame Barrens isn't a spell.)
Elfhame Barrens enters the battlefield tapped unless you control an enchantment.
Green creatures get +1/+1.
: Add or to your mana pool.
Put Elfhame Barrens on top of your library: Add to your mana pool.
: Add 
or 
to your mana pool.
to your mana pool. 
