Question
Hello - I found a flower wich looks like a lady slipper = but was told it was not and is rare look alike that blooms once every seven years - would you happen to know the name of such a look alike so I can look it up and see if I was informed correctly - thank you

Answer
Ladyslipper is an Orchid.  I cannot think of another flower that resembles this one.  There are believe it or not quite a few flowers that take 5, 6, 7, even 8 years to bloom and wait that long before re-blooming: Strelitzia reginae 'Bird of Paradise'. Titan Arum 'Corpse Flower'.  Paphiopedilum 'Ladyslipper Orchid'.  

One of the prettier specimens is the Karvy Flower:

http://www.flowersofindia.net/catalog/slides/Karvy.html

This does not look like a Ladyslipper.

Are you sure you DON'T have a Ladyslipper Orchid?  Please view the photos on this website:

http://www.wickfordorchids.com/paphiopedilum_orchids_for_sale.htm

and confirm this is DEFINITELY not a Ladyslipper.

If you are correct and you are certain this is not a Ladyslipper Orchid, can you tell me where you live and where you found this plant?  It will help me answer your question better.  Thanks.