My Philodendron lacerum started flowering some time back but it always seemed their inflorescences stayed tightly wrapped up in the spathes. The other day, however, I noticed one of the spathes had opened up and stayed open for a day or so. Then it 'rolled' itself back up and looks just like all the others that (apparently) have never opened. It's not looking old or withered, you wouldn't pick that is was any different to the others. I'm watching them more closely now because I don't know how many might have gone through that open-and-close-back-up process while I wasn't watching. Sneaky little devils, LOL.