Atala Butterflies use Coontie as their host plant. They stay local, and need a dozen or more plants in your yard or butterfly garden to survive as a colony, unless your neighbor has enough to make up the difference.

The beautiful red and yellow Atala caterpillars will munch up the leaves, and if you don't have enough plants for your butterflies, you'll quickly end up with bare plants:

I usually see the butterflies lay their eggs on the underside of the most tender new Coontie leaves, but when all of the leaves are nibbled, they'll lay their eggs on the Coontie seed cones as well:

My first Coontie 'died', I'm guessing from lack of water. Oddly enough, the plant recently sprouted new leaves, and it's been at least a year since it turned brown and vanished. It's not a plant to give up on; it sure surprised me!

For more information about Coontie, try looking up cycad.

Coontie (Zamia floridana, or Zamia pumila) has an interesting history.  It was harvested for food (don't try this at home, the root is poisonous without proper processing to remove a water soluble toxin, and besides, the butterflies need it), and so much of it was removed that the Atala was thought to be extinct when they made the endangered species list.  The Electronic Data Information Source of UF/IFAS Extension has the most comprehensive write up I've read about Coontie and Atala Butterflies and their history here.