Can anyone help identify this plant?

[Timothy Albert Haas]

When I was a teenager, I got this plant from a teacher of mine.  She told 
me it was called "Star of Bethlehem."  It is clearly some type of 
succulent:  thick leaves and tolerated drying out completely.  The leaves 
are flat with scolloped edges.  The seem to emerge from the stem almost 
like the stem just flattens out.  They are like 6-12 inches long, and 
perhaps 2 inches wide.  There is no symmetrical shape to the plants, 
leaves and stems seem to can get (for my family, at least) 3-4 feet 
tall.  It blooms only at night, and the blossom will open only once--by 
the next morning it has closed.  The stem the blossom is on sort of grows 
downward, then curves upward slightly, sort of like a side-ward "J".  Any 
suggestion what this might be, and a book that would help in a positive 
identification?