A recent conversation with a friend prompted me to search the web for accurate information about the Tiger Lily. I run across this question about once a year. It appears that the  true Tiger Lily has become confused with the common day lily (also known as the ditch lily), or perhaps I have become confused. My source for most any botanic question is pretty reliable, but doing a little research can never hurt. It has always been my understanding that the Tiger Lily is actually related to the Oriental varieties and has a stem similar to the oriental varieties. Others identify the Tiger Lily as the variety I have always known as the Day or Ditch Lily. This website has images and a good description of the Tiger Lily (as I have always known it to be):

www.americanmeadows.com/Perennials/PerennialLilyFlowerBulbs/RedTigerLilyBulbs.aspx

Wikepedia also has some good information about Tiger Lilies at:

http://en.wikipedia.org/wiki/Tiger_lily

The Tiger Lily can be identified by its tall stalk with leaves that grow off the stalk, orange flowers with big black dots and stem bulbils that will fall to the ground and take root to form new lily plants.

Many websites identify certain varieties of the Day Lily as a Tiger Lily, but I have a strong suspicion that this is a propogation of misinformation as so often occurs on the web. The poor Tiger Lily has somehow lost its identity. I'm going to stand by my assertion that the Tiger Lily is a close kin to other Oriental Lilies and bears little resemblance to its cousin the Day Lily, until or unless someone can give me really good evidence to change my mind - please feel free to email me and argue your point!