Plant ID needed

I inherited a plant from my mother that has since passed away. This plant only blooms once every 7 years. Can you please tell me what kind of plant this is?

Thanks.

http://www.deuce-ii.com/images/DSC01086.jpg

 

Looks like Hymenocallis

 

Peruvian daffodil. Should bloom every year. Bulbous plants like this may take something like seven years to reach flowering size when raised from seed, but once flowering commences it normally occurs annually.