"Al" wrote in message ...
With regard to the three flower parts of the inner whorl; the two petals and
the lip. Evolution has changed the 'bottom' petal into a lip.

Great post! Just a minor nitpick: It is the upper petal that is
converted into the lip. Most orchid buds twist 180 degrees before
they open, so that the lip moves to the bottom of the open flower.
Some orchids do not twist, and the lip remains where it started, at
the top. But perhaps that's why you put 'bottom' in quotes...

Nick