Tiger Lily can be found from a number of mail order places. I've had good luck with Brent and Becky's bulbs.
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-Helen

http://www.brentandbeckysbulbs.com/summer/productview/?sku=84-36

Here is a link that might be useful: Brent and Becky's Tiger Lily

I love the true tiger lilies. Usually K-mart has them by the bag/box. The big box bulbs might not be premium size (but the price isn't premium either); however, I've bought them - they sprout, bloom, spread by the little bulbils that form in the leaf axils and drop on the ground, and come back year after year bigger and better.

Don't know your location, but finding bulbs locally often depends on where you are. Here, the summer flowering bulbs are in the stores in the early fall for immediate planting. In warm/warmer climates they might be available in the spring or all year 'round.

You might get lucky and find one already grown and ready to bloom at a local garden center. Even though they're common, people still love them.

If you are not successful in finding it for sale, I will be happy to send you a bulb or two and many bulbets in the fall. I have way too many of them. diene