Opening of the limb

As the limb of the spathe opens mostly in the late night - at me at least - the process of opening is selden seen. Modern camera's can take pictures at intervals and you can use them unattended to make a serie of pictures. You must have some experience to guess when you have to start the camera, but you can check it every few hours and start again.
The process of opening is not well understood as far as I know. As you see no damage on the margings of the limb, it may be something like a 'zip fastener', specialized cells losing their turgor, losing grip to the opposite margin and the tension in the limb do split it.
The process of opening goes fast, in a few minutes it is done.

C. ciliata var. ciliata

The frames are made every 2 minutes. You can stop the movie and go step by step up / down